Chapter 30 Drugs

Question 1

Acetaminophen – oxycodone hydrochloride

Answer 1

Acetaminophen – oxycodone hydrochloride (Percocet, Endo; Roxicet, Roxane) – [tabs 325/2.5, 325/5, 325/7.5, 325/10, 500/7.5, 650/10 mg] Indic/dosage: pain, moderate to moderate-severe: acetaminophen 325 to 650 mg/oxycodone 2.5 to 10 mg orally q6h prn; max 4,000 mg acetaminophen/day
Action: acetaminophen is a nonopiate and nonsalicylate analgesic and antipyretic drug; oxycodone hydrochloride, a semisynthetic pure opioid agonist, has actions similar in quality with those of morphine and acts predominantly on the CNS and organs composed of smooth muscle
Contra: bronchial asthma, known or suspected paralytic ileus, and respiratory depression
Warn/prec: chronic administration may result in psychic and physical dependence and tolerance, concomitant use of other CNS depressants (including alcohol), elderly or debilitated patients, and in pregnancy C (acetaminophen) and B (oxycodone)
Adverse reactions: constipation, nausea/vomiting, dizziness, light-headedness, and somnolence

Question 2

Alendronate

Answer 2

Alendronate (Fosamax, Merck) – [tabs 5, 10, 35, 40, 70 mg]
Indic/dosage: osteoporosis prevention: 5 mg qd or 35 mg qwk; osteoporosis treatment: 10 mg qd or 70 mg qwk; Paget’s disease: 40 mg qd × 6 months; all tablets should be taken ≥30 minutes before first food or beverage of the day, with a full glass of water; avoid lying down for at least 30 minutes
Action: bisphosphonates act to inhibit normal and abnormal bone resorption; as a result, an asymptomatic reduction in serum Ca and PO4 is noted
Contra: hypocalcemia, severe renal dysfunction, and dysphagia
Warn/prec: upper GI disease and pregnancy C
Adverse reactions: esophagitis, GI distress, headache, myalgias, arthralgias, back pain, dysphagia, abdominal distension, chest pain, peripheral edema, flulike symptoms, and esophageal ulcer

Question 3

Amantadine

Answer 3

Amantadine (Symmetrel, Endo) – [caps 100 mg, syrup 50 mg/5 mL] Indic/dosage: Parkinson’s disease/syndrome: 100 mg bid, can increase to 400 mg/day after one to several weeks, start at 100 mg qd for those on other anti-Parkinson’s medications or medically ill patients; treatment or prophylaxis for influenza A: 200 mg initially, then 100 mg qd; off-label for poor arousal or inattention in TBI: 100 mg bid; off-label for postpolio syndrome pain, fatigue in MS as well as TBI, and hyperthermia of central origin in TBI
Action: blocks ion channels (nicotinic ACh, M2 ionic channel in influenza A); also believed to release dopamine from intact dopaminergic terminals
Warn/prec : seizure disorder, CHF, renal disease, and pregnancy C; withdrawal from amantadine should be gradual
Adverse reactions: (usually well-tolerated) dizziness, nausea, nervousness, ataxia, insomnia, dry mouth, GI hypomotility, urinary retention, changes in mood, confusion, hallucinations, CHF, edema, orthostatic hypotension, and livedo reticularis (particularly women)

Question 4

Amitriptyline

Answer 4

Amitriptyline (Elavil, Merck) – [tabs 10, 25, 50, 75, 100, 150 mg]
Indic/dosage: depression: 50 to 150 mg qhs (for elderly 10 mg tid and 20 mg qhs may be sufficient; reduce dose for hepatic impairment); off-label for neuropathic pain (start at lower doses than for depression)
Action: tertiary amine tricyclic, norepinephrine (NE)/serotonin reuptake inhibitor; also has anti-α1-adrenergic and potent antimuscarinic properties; may potentiate analgesic effect of opioids
Contra: acute post-MI and concomitant monoamine oxidase inhibitor (MAOI) use
Warn/prec : cardiovascular (CV) disorders (can cause HTN), hyperthyroidism, schizophrenia/paranoia, pregnancy D, and discharge before elective surgery; withdraw gradually after long-term use to avoid insomnia and abdominal discomfort
Adverse reactions: dry mouth, blurred vision, constipation, urinary retention, CV effects (tachycardia and prolongation of AV conduction), weight gain, somnolence, seizures, photosensitivity, GI distress, leukopenia, gynecomastia, testicular swelling, sexual dysfunction, and menstrual irregularity
Monitoring: baseline and periodic leukocyte and differential counts, LFTs, and ECG. Patients with CV issues require surveillance

Question 5

Baclofen

Answer 5

Baclofen (Lioresal, Novartis) – [tabs 10, 20 mg, intrathecal (IT)]
Indic/dosage : spasticity: titrate to a maximum dose of 20 mg qid as follows: 5 mg tid × 3 days, then 10 mg tid × 3 days, then 15 mg tid × 3 days, then 20 mg tid × 3 days, increase as needed; consider IT if oral in effective but titration limited by side effects; no indication of oral form for spasticity due to stroke, Parkinson’s disease, or CP
Action: analog of 7-aminobutyric acid (GABA) thought to bind to GABA-B receptors, inhibiting Ca influx into presynaptic terminals and suppressing spinal cord excitatory neurotransmitters
Warn/prec : impaired renal function, risk of seizure if withdrawn too quickly (therefore, should taper off over =1 week), and pregnancy C
Adverse reactions: Oral baclofen: drowsiness, dizziness, headache, nausea/ vomiting, lassitude, GI upset, urinary frequency, CNS depression, confusion, slurred speech, nasal congestion, seizures, blurred vision, weakness, hypotonia, HTN, CV collapse, respiratory failure, rash, pruritus, and increased LFTs; IT baclofen: fatigue and drowsiness
Overdosage: IV physostigmine 1 to 2 mg. Also see p. 213 for details on IT baclofen

Question 6

Bisacodyl

Answer 6

Bisacodyl (Dulcolax, Boehringer Ingelheim) – [oral tab 5 mg, rectal suppository 10 mg]
Indic/dosage: constipation: 5 to 15 mg po qd up to 30 mg/day- or 10 mg suppository rectally qd
Action: stimulates enteric nerves to cause colonic mass movements, a contact laxative; increases fluid and NaCl secretion and increases peristalsis
Contra: appendicitis, intestinal obstruction, and gastroenteritis
Warn/prec: abdominal pain, nausea, vomiting, rectal bleeding, inflammatory bowel disease, use for more than 7 days is not recommended, and pregnancy A
Adverse reactions: abdominal colic, abdominal discomfort, diarrhea, and proctitis

Question 7

Capsaicin

Answer 7

Capsaicin (Zostrix, Medicis) – [cream 0.025%, 0.075%, both OTC]
Indic/dosage: FDA-approved for postherpetic neuralgia; commonly used for OA and neuropathic pain: apply a thin film to affected areas tid to qid; may require ongoing use for effect; experimental intravesical instillation inhibits contractions in neurogenic bladders
Action: evidence suggests that capsaicin depletes the pain neurotrans-mitter substance P from unmyelinated peripheral neurons
Warn/prec: wash hands after application, avoid contact with eyes, and avoid heating pads in treated areas
Adverse reactions: local burning sensation, which typically improves with repeated use, but may not be tolerated by some

Question 8

Carbamazepine

Answer 8

Carbamazepine (Tegretol, Novartis) – [tabs 100, 200 mg, oral suspension 100 mg/5 mL]
Indic/dosage: epilepsy: start at 200 mg bid; trigeminal neuralgia: start at 100 mg qd; off-label for neuropathic pain: start at 100 mg bid; maximum dose for all indications is 1,200 mg/day, usually divided in tid doses, increase doses each week by ≤200 mg/day
Action: unknown, but related to the tricyclic antidepressants (TCAs); may be a result of Na channel blockade in rapidly firing neurons and reduced excitatory synaptic transmission in the trigeminal nucleus
Contra: TCA hypersensitivity, history of bone marrow depression, and concomitant use of MAOIs (or within 14 days of discharge)
Warn/prec: impaired liver/renal function, hyponatremia, pregnancy C, and numerous drug interactions
Adverse reactions: initially dizziness, ataxia, drowsiness, nausea/vomiting, but usually subside spontaneously within a week, bone marrow suppression, hepato/nephrotoxicity, nystagmus, rash, Stevens-Johnson syndrome (SJS), and arrhythmias
Monitoring: pretreatment CBC, BUN, LFTs, and Fe, with periodic follow-up (frequency guidelines not established)

Question 9

Celecoxib

Answer 9

Celecoxib (Celebrex, Pfizer/Searle/Pharmacia) – [caps 100, 200 mg]
Indic/dosage: OA: 200 mg qd or 100 mg bid; rheumatoid arthritis (RA): 100 to 200 mg bid; acute pain/dysmenorrhea: 400 mg initially, followed by 200 mg if needed on first day, then 200 mg bid prn
Action: COX-2 selective NSAIDs
Contra: hypersensitivity to sulfonamides, ASA, and NSAIDs
Warn/prec: HTN, CHF, history of GI bleed, and renal insufficiency; monitor INRs closely with concomitant warfarin treatment, pregnancy C, and nasal polyps
Adverse reactions: edema, GI distress/bleed, thrombocytopenia, nephro/hepatotoxicity, bronchospasm, and agranulocytosis. Note: In the CLASS study,1 annual incidence of upper GI ulcer complications (bleeding, perforation, and obstruction) for celecoxib 200 mg bid versus NSAIDs (ibuprofen 800 mg tid or diclofenac 75 mg bid) was 0.76% versus 1.45%; when combined with symptomatic ulcers, annual incidence was 2.08% versus 3.54% (p = 0.02)

Question 10

Clonidine

Answer 10

Clonidine (Catapres, Boehringer Ingelheim) – [tabs 0.1, 0.2, 0.3 mg, trans-dermal therapeutic system (TTS) qwk patch 0.1/24, 0.2/24, 0.3 mg/ 24 h]
Indic/dosage: HTN: start orally at 0.1 to 0.3 mg bid or TTS 0.1 mg/24 h qwk, maximum dose is 2.4 mg/day orally or TTS 0.3 mg/24 h qwk; off-label for spasticity: dosing similar to HTN; IT clonidine used investigationally for spasticity and neuropathic pain
Action: central α-adrenergic agonist that ↓ sympathetic discharge Warn/prec: CV disease, impaired liver/renal function, withdraw gradually to avoid rebound HTN, and pregnancy C
Adverse reactions: dry mouth/eyes, headache, dizziness, nausea, constipation, sedation, weakness, fatigue, orthostatic hypotension, edema, anorexia, erectile dysfunction, joint pain, and leg cramps

Question 11

Cyclobenzaprine

Answer 11

Cyclobenzaprine (Flexeril, Merck) – [tab 10 mg]
Indic/dosage: muscle spasm due to acute painful musculoskeletal conditions: 10 mg tid, maximum 60 mg/day, not to exceed 2 to 3 weeks
Action: structurally related to the TCAs; thought to act on the brain stem to reduce skeletal muscle hyperactivity, but not effective for spasticity of central origin
Contra: TCA hypersensitivity, concomitant MAOIs (or within 14 days of discharge), and recovery from acute MI, CHF, arrhythmias, conduction disturbances, and hyperthyroidism
Warn/prec: glaucoma, prostatic hypertrophy, and pregnancy B
Adverse reactions: drowsiness, dizziness, dry mouth, weakness, taste changes, fatigue, paresthesias, nausea, insomnia, blurred vision, seizures, hepatitis, and tachycardia

Question 12

Dantrolene

Answer 12

Dantrolene (Dantrium, Procter & Gamble) – [caps 25, 50, 100 mg, injection] Indic/dosage: spasticity: start at 25 mg qd, increase by 25 mg q4-7d to a maximum of 400 mg/day divided into bid–qid (considered the oral agent of choice in TBI due to peripheral action and less CNS side effects); off-label for malignant hyperthermia: 2 mg/kg IV push until symptoms subside or cumulative dose of 10 mg/kg reached; also off-label for heat stroke and cocaine overdose rigidity
Action: reduces excitation–contraction coupling via reduction of sarcoplasmic reticulum Ca release
Contra: active liver disease and lactation
Warn/prec : risk of hepatic dysfunction higher in women or if >35 years, cardiomyopathy or pulmonary disease present, and pregnancy C
Adverse reactions: weakness, malaise, sedation, dizziness, nausea, diarrhea, acnelike rash, pruritus, headache, insomnia, photosensitivity, fatal/nonfatal hepatotoxicity (most commonly 3 to 12 months after initiation of treatment, most cases resolve with discharge), and seizures
Monitoring: baseline/periodic LFTs

Question 13

Diazepam

Answer 13

Diazepam (Valium, Roche) – [tabs 2, 5, 10 mg, oral solution 5 mg/5 mL, 5 g/1 mL, injection]
Indic/dosage: skeletal muscle spasticity due to local reflex spasm, UMN spasticity, athetosis, and stiff-man syndrome: 2 to 10 mg po/IM tid– qid (geriatric patient, 1 to 2.5 mg qd–bid); anxiety dosing similar to spasticity; EtOH withdrawal: initially 2 to 5 mg IV, repeat q3-4h prn; status epilepticus: 0.2 to 0.5 mg/kg/dose IV q15-30min to a maximum of 30 mg
Action: proposed mechanism for antispasticity effect is a postsynaptic facilitation of spinal cord GABA w/o a direct GABA-mimetic effect
Contra: CNS depression and acute angle glaucoma
Warn/prec : class IV, impaired liver/renal function, depression may worsen with use, and pregnancy D
Adverse reactions: sedation, “hangover,” dizziness, ataxia, diplopia, hypotension, confusion, constipation, urinary retention/incontinence, anterograde amnesia, dependency, withdrawal syndrome, bone marrow suppression, rash, fever, hepatotoxicity, blood dyscrasias, and injection site reaction (local pain and thrombophlebitis); apnea/cardiac arrest (rare, typically only after IV administration or in elderly or medically ill patients)

Question 14

Docusate sodium

Answer 14

Docusate sodium (Colace, Purdue Products LP) – [tabs 50, 100 mg]
Indic/dosage : constipation: 50 to 200 mg po qd or in divided doses 2 to 4× daily; 50 to 100 mg rectally as an enema
Action: actively draws water into stool, thus softening stool and achieving ease in bowel movement
Contra: concomitant use of mineral oil, intestinal obstruction, acute abdominal pain, and nausea/vomiting
Warn/prec : sudden change in bowel habits > 2 weeks duration, use > 1 week, rectal bleeding, and pregnancy A
Adverse reactions: abnormal taste in mouth, diarrhea, nausea, cramping, and hepatotoxicity (rare)

Question 15

Etanercept

Answer 15

Etanercept (Enbrel, Amgen) – [subcutaneous (SC) powder for solution 25 mg, SC: 50 mg/mL]
Indic/dosage: ankylosing spondylitis, psoriatic arthritis, RA (moderate to severe): in each case, 50 mg SC qwk given as one 50 mg injection or two 25 mg injections in one day or one 25 mg injection given twice weekly, 72 to 96 hours apart
Action: dimeric soluble form of the p75 TNF receptor that specifically binds TNF-α and TNF-β, binding of etanercept to TNF renders it biologically inactive; also modulates biologic responses that are induced or regulated by TNF, including expression of adhesion molecules responsible for leukocyte migration, serum levels of cytokines, and serum levels of matrix metalloproteinase
Contra: sepsis
Warn/prec: infection, chronic or recurring, TB, alcoholic hepatitis, demyelinating disorders, pancytopenia, aplastic anemia, malignancies, concomitant use of abatacept, anakinra, cyclophosphamide, or live vaccines is not recommended, and pregnancy C
Adverse reactions: injection site reaction, headache, and abdominal pain

Question 16

Etidronate

Answer 16

Etidronate (Didronel, Procter & Gamble) – [tabs 200, 400 mg]
Indic/dosage: Paget’s disease: 5 to 10 mg/kg qd, not to exceed 6 months, or 11 to 20 mg/kg qd, not to exceed 3 months; HO following SCI: 20 mg/kg qd × 2 weeks, then 10 mg/kg qd × 10 weeks; HO following total hip replacement: 20 mg/kg qd × 1 month preoperative, 20 mg/kg qd × 3 months postoperative
Action: as with other bisphosphonates, it inhibits hydroxyapatite crystal growth by preventing precipitation of soluble amorphous CaPO4; also slows osteoblastic and osteoclastic activities
Contra: renal impairment
Warn/prec: CHF, enterocolitis, long bone fracture, and pregnancy C
Adverse reactions: nausea/vomiting, GI distress, osteomalacia/inhibition of bone mineralization, fractures, bone pain, seizures, angioedema, and stomatitis

Question 17

Gabapentin

Answer 17

Gabapentin (Neurontin, Parke-Davis) – [caps 100, 300, 400 mg, tabs 600, 800 mg, solution 50 mg/mL]
Indic/dosage: partial seizures with or w/o 2° generalization: 300 mg qhs on day 1, 300 mg bid on day 2, 300 mg tid on day 3, continue to titrate as tolerated to effect, up to 3,600 mg/day; off-label for neuropathic pain: similar dosing; off-label second-line treatment for spasticity (see p. 210)
Action: unknown; a GABA analog w/o activity at GABA receptors; hypothesized to alter the concentration or metabolism of cerebral amino acids
Warn/prec: impaired renal function and pregnancy C; discharge gradually over 1 week (no known drug interactions)
Adverse reactions: initially somnolence, dizziness, ataxia, but these usually resolve within 2 weeks of starting the drug, fatigue, nystagmus, tremor, diplopia, nausea, nervousness, dysarthria, weight gain, leukopenia, thrombocytopenia, dyspepsia, depression, periorbital edema, and myalgias.

Question 18

Infliximab

Answer 18

Infliximab (Remicade, Centocor Ortho Biotech, Inc.) – [IV powder for solution 100 mg]
Indic/dosage: ankylosing spondylitis: 5 mg/kg IV over at least 2 hours given at weeks 0, 2, and 6, then q6wk thereafter; psoriatic arthritis: 5 mg/kg IV over at least 2 hours given at weeks 0, 2, and 6, then every 8 weeks; may be given with or without methotrexate; RA (moderate to severe), in combination with methotrexate: 3 mg/kg IV over at least 2 hours given at weeks 0, 2, and 6, then every 8 weeks in combination with methotrexate; may increase dose up to 10 mg/kg IV or give 3 mg/kg IV every 4 weeks in patients with an incomplete response
Action: chimeric human-murine immunoglobulin (IgG1κ) monoclonal antibody that binds specifically to TNF-α, a proinflammatory cytokine; neutralizes the biological activity of TNF-α (induction of proinflammatory cytokines, enhancement of leukocyte migration, and stimulation of neutrophil and eosinophil functions)
Contra: CHF
Warn/prec : serious infections, TB, CHF, COPD, CNS/peripheral demy-elinating disorders, concomitant use of anakinra or live vaccines is not recommended, and pregnancy C
Adverse reactions: headache, nausea, rash, and fatigue

Question 19

Lactulose

Answer 19

Lactulose (Enulose, Barre-National) – [oral solution, oral syrup, solution: all 10 g/15 mL]
Indic/dosage: constipation: 15 to 30 mL po qd for 24 to 48 hours; may be increased to 60 mL/day if needed
Action: synthetic disaccharide; bacteria in the colon degrade lactulose into lactic acid, acetic acid, and formic acid, resulting in an increase in osmotic pressure and acidification of intestinal contents which in turn softens the stool by promoting stool water content
Contra: galactosemia
Warn/prec : diabetes and pregnancy B
Adverse reactions: bloating, diarrhea, epigastric pain, flatulence, and nausea/vomiting

Question 20

Leflunomide

Answer 20

Leflunomide (Arava, Sanofi Aventis) – [oral tab: 10, 20 mg]
Indic/dosage : RA: loading dose, 100 mg po qd for 3 days; for maintenance in RA, 20 mg po qd; may reduce dose to 10 mg daily if higher doses not tolerated
Action: immunomodulatory agent, inhibits dihydroorotate dehydrogenase; antiinflammatory effects have been demonstrated in in vivo and in vitro experimental models; antiproliferative activity
Contra: pregnancy or potential for pregnancy
Warn/prec : liver injury, bone marrow dysplasia, pancytopenia, agranulocytosis, thrombocytopenia, immunodeficiency, infections, and pregnancy X
Adverse reactions: diarrhea, alopecia, rash, HTN, increased liver enzymes, and SJS

Question 21

Lidocaine patch

Answer 21

Lidocaine patch (Lidoderm, Endo Pharmaceuticals) – [patch 5% (10×14 cm) ]
Indic/dosage: FDA-approved in 1999 to treat postherpetic neuralgia: apply ≤3 patches on intact skin over the most symptomatic area qd (12 hours on/12 hours off); off-label for other types of neuropathic pain
Action: diffusion of lidocaine into the local epidermis/dermis is thought to block conduction of impulses (inhibits Ca-mediated Na and K ion fluxes) and stabilize neuronal membranes; provides direct local analgesia w/o complete anesthetic block
Warn/prec : do not reuse patches; avoid showers/swimming with patch on; when used appropriately, mean peak serum levels due to systemic absorption may reach about one-tenth the therapeutic level used for antiarrhythmia (these patches are safe); caution in patients with hepatic failure or on antiarrhythmics; and pregnancy B
Adverse reactions: initially, local erythema, edema, and/or paresthesias, usually mild and resolves within minutes to 1 hour

Question 22

Magnesium citrate

Answer 22

Magnesium citrate (Citroma, Swan) – [oral solution 1.75 g/30 mL]
Indic/dosage: constipation: 150 to 300 mL (1.745 g/30 mL solution) po once, may repeat prn
Action: attracts water through the tissues via osmosis, once in the intestine can attract enough water into the intestine to induce defecation; additional water helps to create more feces, which naturally stimulates bowel motility
Contra: heart block, severe renal disease, and rectal bleeding
Warn/prec: rectal blood, saline cathartics without adequate fluid replacement can produce dehydration, and pregnancy A
Adverse reactions: diarrhea, dizziness, and hypermagnesemia

Question 23

Metaxalone

Answer 23

Metaxalone (Skelaxin, Pfizer, Inc.) – [tab 400 mg]
Indic/dosage: relief of discomfort associated with acute, painful musculoskeletal conditions: 800 mg tid–qid
Action: not established, but may be due to general CNS depression; no direct action on contractile mechanism of striated muscle, motor end plate, or nerve fiber
Contra: history of anemias and significantly impaired renal/hepatic function
Warn/prec: liver impairment and pregnancy (unknown)
Adverse reactions: drowsiness, paradoxic CNS excitation, nervousness, nausea/vomiting, irritability, dizziness, rash, leukopenia, hemolytic anemia, and jaundice

Question 24

Methylphenidate

Answer 24

Methylphenidate (Ritalin, Novartis) – [tabs 5, 10, 20 mg]
Indic/dosage: ADHD; narcolepsy; off-label for depression (as a stimulant) in elderly, cancer, and poststroke patients: 10 to 15 mg/day up to 40 to 60 mg/day in 2 to 3 divided doses, typically 30 to 45 minutes before meals
Action: a mild CNS stimulant with action similar to amphetamines (believed to facilitate NE and dopamine release)
Contra: glaucoma, Tourette syndrome, severe anxiety, and agitation
Warn/prec: class II, HTN, seizure disorder, CV disease, numerous drug interactions, and pregnancy C
Adverse reactions: nervousness, insomnia, anorexia, headache, dizziness, dys-kinesia, rash, HTN, tachycardia, palpitations, GI distress, dependency, leukopenia, exfoliative dermatitis, erythema multiforme, motor tics, elevated LFTs, ventricular arrhythmias, and thrombocytopenia

Question 25

Midodrine

Answer 25

Midodrine (ProAmatine, Shire Pharmaceuticals) – [tabs 2.5, 5, 10 mg]
Indic/dosage: 10 mg, 3× daily at approximately 4-hour intervals for the treatment of symptomatic orthostatic hypotension. Dosing should primarily take place during the daytime hours when the patient is upright. Renal dosing: initiate treatment using 2.5 mg doses
Action: long-acting, selective α-adrenergic agonist
Contra: acute renal disease/urinary retention, pheochromocytoma, severe organic heart disease or CHF, supine HTN, and persistent and excessive thyrotoxicosis
Warn/prec: OTC drugs that cause elevations in BP, concomitant use with other therapeutic agents that may cause vasoconstriction, concurrent use with digitalis glycosides, β-blockers, or other agents that directly or indirectly reduce heart rate, DM, hepatic insufficiency, patients receiving fludrocortisone for vision disorders (risk of elevated intraocular pressure), and urinary retention
Adverse reactions: bradyarrhythmia, HTN, orthostatic hypotension exacerbation, urinary urgency, urinary retention, urinary frequency, sleep disturbances, headache, dizziness, restlessness, heartburn, and nausea; pregnancy C

Question 26

Modafinil

Answer 26

Modafinil (Provigil, Caphalon, Inc.) – [tabs 100, 200 mg]
Indic/dosage: FDA-approved in 1998 for excessive daytime sleepiness (EDS) due to narcolepsy: 200 mg qd, 100 mg in liver impairment; off-label for fatigue due to MS and to improve alertness post-TBI; being studied in Alzheimer’s disease, age-related memory decline, and EDS due to sleep and neurologic disorders
Action: thought to act on the anterior hypothalamus and other CNS centers; increases glutaminergic while reducing GABAergic transmission
Contra: cardiac disease
Warn/prec: class IV, impaired liver/renal function, and pregnancy C
Adverse reactions: headache, nausea, infection (2° to decreased immune function due to sleep reduction), nervousness, anxiety, insomnia, rhinitis, diarrhea, dry mouth, anorexia, dizziness, and depression
Monitoring: consider periodic LFTs

Question 27

Oxybutynin

Answer 27

Oxybutynin (Ditropan, Janssen) – [tab 5 mg, oral suspension 5 mg/5 mL]
Indic/dosage: bladder instability: 5 mg bid–tid, maximum 5 mg qid
Action: muscarinic blocker with a direct antispasmodic effect on smooth muscle
Contra: myasthenia gravis, GI obstruction, ileus, ulcerative colitis, mega-colon, obstructive uropathy, and glaucoma
Warn/prec: impaired liver/renal function and pregnancy B
Adverse reactions: dry mouth, nausea, blurred vision, tachycardia, flushing, decreased sweating, dry eyes, constipation, urinary retention, dizziness, drowsiness, insomnia, hallucinations, restlessness, cycloplegia, and erectile dysfunction

Question 28

Oxycontin

Answer 28

Oxycontin (OxyContin, Purdue Pharma LP; Roxicodone, Xanodyne Pharmaceuticals, Inc.) – [oral caps 5 mg; oral solution 5 mg/5 mL, 20 mg/mL; oral tabs 5, 10, 15, 20, 30 mg]
Indic/dosage: pain (moderate to severe; immediate-release capsules): initial, 5 mg po q6h prn; adjust based on pain severity and patient response; pain (moderate to severe; controlled-release tablets): opi-oid-naive patients, 10 mg po q12h; titrate up to 40 mg po q12h prn based on patient’s response; maximum daily dose, 80 mg; maximum single dose, 40 mg; single dose greater than 40 mg or a total daily dose greater than 80 mg is reserved for opioid-tolerant patients only
Action: opioid analgesic with actions similar to morphine, a pure agonist opioid; exact mechanism is unknown, specific CNS opioid receptors for endogenous compounds with opioidlike activity that have been identified throughout the CNS may play a role in the analgesic effects of this drug
Contra: bronchial asthma, paralytic ileus, known or suspected, and respiratory depression
Warn/prec: abuse potential, crushing, cutting, breaking, chewing, or dissolving controlled-release tablets prior to ingestion leads to rapid release and absorption of a potentially fatal dose of oxycodone; concomitant use of other CNS depressants (including alcohol), and elderly or debilitated patients
Adverse reactions: constipation, nausea/vomiting, dizziness, light-headedness, somnolence, and pruritus

Question 29

Phenytoin

Answer 29

Phenytoin (Dilantin, Pfizer, Inc.) – [caps 30, 50, 100 mg; chewable tab 50 mg; oral suspension 125 mg/5 mL; injection]
Indic/dosage: seizure prophylaxis: 4-6 mg/kg/d IV BID-TID. Start by loading 10-20 mg/kg IV divided in 3 doses, 2-4 h apart. max is 400/ dose.
Action: centrally acting modifier of Na, Ca, and K ion transport that results in membrane “stability”; blocks Na channels in a use-dependent manner
Contra: sinus bradycardia, SA block, second/third-degree AV block, and Adams-Stokes syndrome
Warn/prec: hypotension, CV disease, DM, impaired liver/renal function, arrhythmias, thyroid disease, pregnancy D, porphyria, and elderly
Adverse reactions: anorexia, dyspepsia, nausea, ataxia, nystagmus, diplopia, lethargy, insomnia, constipation, tremor, slurred speech, headache, rash, blood dyscrasias, megaloblastic anemia, severe dermatologic reactions, hepatotoxicity, severe CV abnormalities, purple glove syndrome, toxic delirium, lymphoma, SLE, gingival hyperplasia, coarse facies, and osteomalacia
Monitoring: trough level should be drawn after 1 week of regular use to determine steady-state level; draw level 2 to 4 hours after IV loading dose; no strict guidelines for drawing levels after oral loading

Question 30

Prednisone

Answer 30

Prednisone (Organon) – [tabs 1, 2.5, 5, 10, 20, 50 mg; oral solution 5 mg/5 mL]
Indic/dosage: inflammatory disorders: 5 to 60 mg qd
Action: adrenocorticosteroid with glucocorticoid and mineralocorticoid activities
Contra: systemic fungal infection
Warn/prec: seizure disorder, osteoporosis, CHF, DM, HTN, TB, impaired liver function, and pregnancy C
Adverse reactions: edema, mood swings, psychosis, adrenal insufficiency, immunosuppression, peptic ulcer, CHF, insomnia, anxiety, hypokalemia, osteoporosis, appetite change, headache, dizziness, HTN, hyperglycemia, acne, cushingoid features, skin atrophy, ecchymosis, impaired wound healing, and menstrual irregularities

Question 31

Pregabalin

Answer 31

Pregabalin (Lyrica, Pfizer) – [caps 25, 50, 75, 100, 150, 200, 225, 300 mg]
Indic/dosage: diabetic peripheral neuropathy: initial, 50 mg po tid, may be increased to 100 mg po tid within 1 week; fibromyalgia: initial, 75 mg po bid, may be increased to 150 mg po bid within 1 week, no evidence of additional benefit with doses above 450 mg/day; postherpetic neuralgia: initial, 75 mg po bid or 50 mg po tid, may be increased to 300 mg/day within 1 week based on efficacy and tolerability
Action: GABA analog that strongly binds to α2δ site (a subunit of voltage-gated calcium channels) in CNS tissues and reduces calcium-dependent release of several neurotransmitters, possibly by modulation of calcium channel function; however, exact mechanism of action is unknown
Contra: hypersensitivity to pregabalin or any other component of the product
Warn/prec: abrupt discontinuation, risk of adverse events, and increased seizure frequency; angioedema, CHF, increased risk of suicidality, and pregnancy C
Adverse reactions: peripheral edema, weight gain, dizziness, headache, somnolence, and blurred vision

Question 32

Psyllium

Answer 32

Psyllium (Metamucil, Proctor and Gamble) – [seed husks 3 g; seed 5 to 10 g; liquid extract 2 to 4 mL]
Indic/dosage: constipation: seed husks: 3 g, up to tid; seed: 5 to 10 g, up to tid; liquid extract: 2 to 4 mL up to tid
Action: absorbs water from the GI tract, increasing stool bulk
Contra: intestinal obstruction and fecal impaction
Warn/prec: adequate fluid intake is required, inadequate water may cause psyllium to swell and block the throat or intestines, GI obstruction, and pregnancy C
Adverse reactions: abdominal cramps, bronchospasm, diarrhea, and esophageal/GI obstruction

Question 33

Sennosides

Answer 33

Sennosides (Senokot, Purdue Pharma, LP) – [tablet, granules, syrup, tea, suppository]
Indic/dosage: constipation: tablets, oral: 0.5 to 2 g of the crude drug or 20 to 40 mg sennosides with water qhs; granules, oral: 5 mL (326 mg, 1 teaspoon) up to a maximum of 10 mL bid; extra strength tablets, oral: 1 tablet (364 mg) qhs, up to a maximum of 2 tablets bid; syrup, oral: 10 to 15 mL (436 to 654 mg), up to a maximum of 30 mL daily; suppository, rectal: 1 suppository (652 mg) qhs, repeat in 2 hours if necessary
Action: hydroxyanthracene glycosides are not absorbed but converted by microflora of the large intestine into active aglycones; exert a laxative effect on the colon resulting in stimulation of colonic motility and accelerated colonic transit, reducing opportunity for fluid absorption and enhancing the laxative effect
Contra: bowel obstruction, acute inflammation (Crohn’s disease and appendicitis), and pregnancy C
Warn/prec: abdominal pain, nausea/vomiting, and rectal bleeding
Adverse reactions: abdominal pain, nausea, cramps, electrolyte abnormalities, and diarrhea

Question 34

Sildenafil

Answer 34

Sildenafil (Viagra, Pfizer, Inc.) – [tabs 25, 50, 100 mg]
Indic/dosage: erectile dysfunction: start at 50 mg about 1 hour prior to sexual activity, increase up to 100 mg or decrease to 25 mg prn; 25 mg recommended for age >65 years
Action: selective PDE-5 inhibitor that increases cGMP levels and promotes smooth muscle relaxation in the corpus cavernosum
Contra: regular or intermittent nitrate use (may result in death due to severe hypotension); MI/stroke within 6 months
Warn/prec : liver/renal disease, hypotension, penile deformities, seek medical attention for erections >4 hours, no nitrates for cardiac events or autonomic dysreflexia for 24 hours after sildenafil ingestion
Adverse reactions: headache, flushing, dyspepsia, nasal congestion, visual problems (blurred vision, blue tinge, and photophobia), priapism, UTI, diarrhea, dizziness, hypotension, tachycardia, MI, TIAs, and stroke

Question 35

Tamsulosin

Answer 35

Tamsulosin (Flomax, Boehringer Ingelheim Pharmaceuticals, Inc.) – [oral caps 4 mg]
Indic/dosage: benign prostatic hyperplasia: initial, 0.4 mg orally once daily; if no response after 2 to 4 weeks may increase dose to 0.8 mg orally once daily
Action: α1A adrenoceptor antagonist, selectively blocks sympathetic nervous stimulation of the receptor, resulting in relaxation of the smooth muscles of the prostate, prostatic urethra, and bladder neck
Contra: hypersensitivity to tamsulosin or to any component of the product
Warn/prec : orthostasis (postural hypotension, dizziness, and vertigo), concomitant use with strong CYP3A4 inhibitors or other α-adrenergic blocking agents should be avoided, and pregnancy B
Adverse reactions: dizziness, headache, rhinitis, abnormal ejaculation, infectious disease, retinal detachment, and priapism

Question 36

Tizanidine

Answer 36

Tizanidine (Zanaflex, Acorda) – [tab 2, 4 mg]
Indic/dosage : spasticity: no set dosing; sample regimen: start at 2 mg qhs, then q3d increase to 2 mg qam/2 mg qhs→2 mg qam/4 mg qhs→ until 4 mg tid is achieved; maximum dose is 36 mg/day
Action: central α2-adrenergic agonist that reduces spasticity by increasing presynaptic inhibition of motoneurons; reportedly ≈10% of the BP effects of clonidine; peak effects at 1 to 2 hours after administration
Warn/prec: impaired renal/hepatic function and pregnancy C
Adverse reactions: somnolence, weakness, hypotension, dry mouth, dizziness, hepatotoxicity, severe bradycardia, hallucinations, asthenia, UTI, constipation, urinary frequency, flulike symptoms, pharyngitis, rhinitis, and increased spasms

Question 37

Tolterodine

Answer 37

Tolterodine (Detrol, Pfizer, Inc.) – [tabs 1, 2 mg; LA tabs 2, 4 mg]
Indic/dosage: bladder instability: 2 mg bid, 1 mg bid in hepatic dysfunction (with Detrol LA, 2 or 4 mg qd)
Action: muscarinic blocker that exerts a direct antispasmodic effect on smooth muscle
Contra: narrow-angle glaucoma and gastric or urinary retention
Warn/prec : impaired liver/renal function and pregnancy C
Adverse reactions: dry mouth, blurred vision, dry eyes, urinary retention, UTI, somnolence, headache, dizziness, GI distress, upper respiratory infection, flulike symptoms, arthralgia, and pruritus

Question 38

Topiramate

Answer 38

Topiramate (Topamax, Janssen) – [tabs 25, 100, 200 mg; caps 15, 25 mg]
Indic/dosage: FDA-approved in 1997 as an adjunct treatment for partial-onset seizures and mood stabilizer: start at 25 mg bid and increase daily dose to 50 mg/week until therapeutic (typically 200 to 400 mg/ day); Ortho-McNeil pursuing indication for diabetic neuropathy (initial J&J studies not promising); off-label use for neuropathic pain: no established dosing regimen, may start at 25 mg qhs with weekly increases of 25 mg/day; clinical trial to study possible slowing of ALS progression in progress
Action: Na channel blocker, but analgesic mechanisms unclear
Warn/prec: pregnancy C
Adverse reactions: somnolence, dizziness, vision problems, unsteadiness, nausea, paresthesias, psychomotor slowing, nervousness, speech/memory problems, tremor, and confusion

Question 39

Tramadol

Answer 39

Tramadol (Ultram, Janssen) – [tab 50 mg]
Indic/dosage: FDA-approved in 1993 for moderate to moderately severe pain: 50 to 100 mg q4-6h, not to exceed 400 mg/day (elderly: ≤300 mg/ day; creatinine clearance <30 mL/min: dose q12h, ≤200 mg/day; hepatic impairment: 50 mg q12h); one 50-mg tablet is roughly equivalent to one Tylenol #3
Action: centrally acting, synthetic nonopioid analog of codeine that produces analgesia by weak μ-receptor agonism (has 10% of the affinity of codeine), serotonin/NE reuptake blockade, and enhancement of neuronal serotonin release; opioidlike CNS side effects and thus may be better tolerated in injured workers who wish to remain working
Contra: acute EtOH intoxication; use with opioids, psychotropics, or central analgesics
Warn/prec: seizure disorder, head trauma, increased ICP, concomitant MAOI or SSRI, pregnancy C, acute abdominal conditions, and opi-oid dependence
Adverse reactions: vertigo, nausea, constipation, headache, somnolence, vomiting, pruritus, asthenia, sweating, dry mouth, dyspepsia, diarrhea, syncope, orthostatic hypotension, and tachycardia

Question 40

Trazodone

Answer 40

Trazodone (Desyrel, Apothecon; Oleptro, Labopharm) – [tabs 50, 100, 150, 300 mg]
Indic/dosage: depression: 150 to 400 mg in divided doses; off-label for aggressive behavior: 50 mg bid, titrate prn; take with food to enhance bioavailability
Action: triazolopyridine derivative antidepressant; mechanism not fully understood (serotonin reuptake inhibitor in animal models)
Contra: early post-MI period and pregnancy C
Warn/prec: CV disorders, nursing, and discharge before elective surgery
Adverse reactions: drowsiness, nausea/vomiting, dizziness, dry mouth, constipation, urinary retention, hypotension, bitter taste, fatigue, blurred vision, headache, arthralgia, incoordination, tremor, and priapism (≈1:6,000 to 10,000)

Question 41

SAMPLE DOSING OF SELECTED ORAL NSAIDS

Answer 41

Diclofenac (Voltaren) – [tabs 25, 50, 75 mg] 50 to 75 mg bid; Arthrotec (diclofenac/misoprostol) 50 to 75 mg/200 mg bid or 50 mg/200 µg tid
Etodolac (Lodine and Ultradol) – [tabs 200, 300, 400 mg] 200 to 400 mg po bid/tid
Ketoprofen (Orudis) – [tabs 25, 50, 75 mg] 25 to 75 mg tid/qid
Ketorolac (Toradol) – 15 to 30 mg IV/IM q6h or [tab 10 mg] 10 mg po q4-6h; total duration of ketorolac treatment not to exceed 5 days
Meloxicam (Mobic) – [tab 7.5 mg] 7.5 to 15 mg qd
Nabumetone (Relafen) – [tabs 500, 750 mg] 1,000 to 2,000 mg qd or 500 to 1,000 mg bid
Naproxen (Naprosyn and Aleve) – [tabs 250, 375, 500 mg] 250 to 500 mg bid
Oxaprozin (Daypro) – [caps 600 mg] 1,200 mg qd

Question 42

Morphinelike narcotic agonists have activity at the ______ and ______-opioid receptors and possibly the ______-receptors. The μ-receptors mediate ______ analgesia, ______, respiratory and physical depression, miosis, and reduced GI motility. The κ-receptors mediate ______ analgesia, sedation, and miosis.

Answer 42

Morphinelike narcotic agonists have activity at the μ- and κ-opioid receptors and possibly the δ-receptors. The μ-receptors mediate supraspinal analgesia, euphoria, respiratory and physical depression, miosis, and reduced GI motility. The κ-receptors mediate spinal analgesia, sedation, and miosis.

Question 43

Shoulder Bursitis/Rotator Cuff Tendinitis (Lateral Approach)

Answer 43

Shoulder Bursitis/Rotator Cuff Tendinitis (Lateral Approach) – Using a 1.5″ 21G needle, inject a 5-mL mix of 20 mg triamcinolone and local anesthetic to the lateral shoulder 2 cm anterior and inferior to the acro-mial angle at a depth of ≈2 cm below the skin.

Question 44

Lateral Epicondylitis

Answer 44

Lateral Epicondylitis – Rest arm on a table palm down, elbow flexed 45°. Using a 1.5″ 23G needle, inject a 5-mL mix of 10 mg triamcinolone and local anesthetic into the most tender area about the extensor tendon attachment to the lateral epicondyle.

Question 45

Carpal Tunnel

Answer 45

Carpal Tunnel – Supinate the wrist and extend over a towel. Using a 1.5″ 25G needle, inject a 1-mL mix of 10 mg triamcinolone and local anesthetic directed distally at a 60° angle to the skin proximal to the distal wrist crease between the palmaris longus and flexor carpi radialis tendons. The needle is inserted 1 to 2 cm. Median n. anesthesia confirms proper injection; paresthesias may last 1 to 2 weeks. Volume is minimized to reduce postinjection discomfort.

Question 46

De Quervain’s Tenosynovitis

Answer 46

De Quervain’s Tenosynovitis – Place the forearm on a table on its ulnar side in ulnar deviation (support under the distal forearm with towels). Using a 1″ 25G needle, slowly inject a 5-mL mix of 40 mg triamcinolone and local anesthetic at a 45° angle along the APL and EPB sheaths to create a sausagelike wheal. If resistance is encountered, retract the needle to avoid tendinous injection.

Question 47

Knee

Answer 47

Knee – Seat the patient with knees flexed 90° and the feet dangling. Using a 1.5″ 21G needle, inject a 5- to 6-mL mix of 20 to 40 mg triamcinolone and local anesthetic either medially or laterally to the patellar tendon toward the intercondylar notch. Discourage excessive postinjection ambulation × 24 hours.

Question 48

Pes Anserine Bursa

Answer 48

Pes Anserine Bursa – With the patient supine and knee in extension, advance a 1.5″ 21G needle perpendicularly to periosteum at the point of maximal tenderness (medial leg) and then pull back slightly. Inject a 4-mL mix of 20 mg triamcinolone and local anesthetic.

Question 49

Plantar Fascia

Answer 49

Plantar Fascia – Place patient prone on a table with feet extending over the edge. Advance a 1.5″ 23G needle at the point of maximal tenderness near the medial attachment of the plantar fascia to calcaneus. Retract ≈2 mm from the periosteum and inject a 2-mL mix of 20 to 40 mg triamcinolone and local anesthetic.