Chapter 30 Drugs Flashcards
Acetaminophen – oxycodone hydrochloride
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
Alendronate
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
Amantadine
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)
Amitriptyline
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
Baclofen
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
Bisacodyl
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
Capsaicin
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
Carbamazepine
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)
Celecoxib
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)
Clonidine
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
Cyclobenzaprine
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
Dantrolene
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
Diazepam
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)
Docusate sodium
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)
Etanercept
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
Etidronate
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
Gabapentin
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.
Infliximab
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
Lactulose
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
