Drug Interactions For Dental Professionals

Question 1

Antibiotics and contraceptives

Answer 1

CONTRACEPTION
DECREASE effectiveness of oc’s as they dec. plasma levels of oc’s by preventing the recirculation of the drug through the enterohepatic hepatic circulation 

Ask pt. to consider additional contraceptive measure

Mostly ampicillin and tetracycline

Question 2

B- lactams( penicillin and cephalosporin) + allopurinol (lopurin, zyloprim)

Answer 2

GOUT

Avoid ampicillin
Minor ALLERGY reaction to AMPICILLIN Other penicillins not implicated

Question 3

B-lactams + beta blockers ( tenormin , lopressor ,inderal , corgard)

Clit

Answer 3

HYPERTENSION

Prolonged use of ampicillin-serum levels of atenolol are dec.

Axn: When pt takes a b- blocker , there is inc. mediator release from Mast cells- so ANAPHYLACTIC REACTION to penicillin or other drugs maybe more SEVERE

Recommended: Use with caution- let pt know of potential risks

Question 4

B-lactams+ tetracycline and other bacteriostatic antibiotics

Answer 4

Infection, acne or periodontal disease

Effectiveness of penicillin and cephalosporin is DECREASED by bacteriostatic agents.

Avoid interactions

Question 5

Doxycycline and Methotrexate

Answer 5

IMMUNOSUPPRESSION

Interactions can lead to increased methotrexate concentration- so TOXICITY

Select a different antibiotic

Methotrexate is an chemotherapeutic agent and immune system suppressant. Used to treat cancers, autoimmune diseases and ectopic pregnancy

Question 6

Metronidazole and ethanol

Answer 6

Alcohol use or abuse

Severe DISULFIRAM like reaction

Avoid interaction

Question 7

Metronidazole and lithium

Answer 7

MANIC DEPRESSION

Inhibits renal excretion of lithium.. so toxic levels of lithium reached. This causes confusion, ataxia, kidney damage

Avoid interaction

Question 8

Tetracycline / flouroquinolones with antacids

Flouroquinolones
family of broad spectrum, systemic antibacterial agents that have been used widely as therapy of RESPIRATORY and URINARY tract infection

Answer 8

Dyspepsia, gastroesophageal reflux and peptic ulcers
Antacids , dairy processing products and other agents containing divalent( calcium and iron) and trivalent cations.They chelate these AB’s and limit their absorption.

Least influenced- doxycycline

Recommended- avoid interactions

Question 9

Tetracycline/ flouroquinolones and insulin

Answer 9

Diabetes Mellitus

Doxycycline and oxytetracycline ENHANCE the hypoglycaemic effect of exogenous administered insulin.

Recommended- select a different AB or increase carbohydrate intake

Question 10

Antibiotics/antifungal’s metabolized by CYP three A4 and CYP1A2

Example macrolide antibiotics (erythromycin, clarithromycin)
Antifungal’s (ketoconazole, fluconazole)
Interacting with benzodiazepines

Answer 10

Anxiety

Delayed metabolism of benzodiazepines, increasing the pharmacological effects can result in excessive sedation and irrational behaviour

Recommended : reduce the dose of benzodiazepine, or avoid interaction

Question 11

Antibiotics and antifungal’s with buspirone

Answer 11

Depression

Delayed metabolism of buspirone increasing pharmacological effect
Recommended: avoid interaction

Question 12

Antibiotics and antifungal’s with carbamazepine (Tegretol)

Answer 12

Seizure disorder

Increase blood levels of carbamazepine leading to toxicity .

Symptoms include drowsiness, dizziness, nausea, headache, and blurred vision . Hospitalization required.
Recommended : avoid interactions

Question 13

Antibiotics and antifungals with cisapride

Answer 13

Gastro-oesophageal reflex delayed metabolism of cisapride causes pharmacological effects and risk for cardiac arrhythmia and sudden death
Recommended avoid interaction

Question 14

antibiotics and antifungals with cyclosporine

Answer 14

Organ transplantation, enhanced immunosuppression and nephrotoxicity recommended avoid interaction

Question 15

I biotics and antifungal with disopyramide quinidine

Answer 15

Cardiac arrhythmias inhibits CYP three A4 metabolism, resulting in large increase an anti-arrhythmia drug that can lead to arrhythmias
recommended avoid interaction

Question 16

Antibiotics and antifungals+ lovastatin, pravastatin, Simba, Staten, and other statins

Answer 16

Hyper lipidaemia
Increase plasma, concentration of statin drugs.

may result in muscle (eosinophilia) myalgia and rhabdomyolysis(muscle breakdown and pin) and acute renal failure
Recommended avoid interaction

Question 17

I biotics and antifungal‘s+ Pimozide

Answer 17

Antipsychotic used to control motor actions

May result in increased concentration of by Musaid, and possibly prolongation of the QT interval
Recommended avoid interaction

Question 18

Antibiotic and antifungal with prednisone or methylprednisolone

Answer 18

Auto immune disorders or organ transplant

Increased risk of Cushing’s syndrome and immunosuppression
Recommended monitor patient and shorten duration of antibiotic administration if possible

Question 19

Antibiotic and antifungal+ Theo Filene(theodur)

Answer 19

Asthma
Erythromycin inhibits the metabolism of Theo Filene, causing toxic sedum levels, symptoms of toxicity, headache, nausea, vomiting, confusion, thirst, cardiac arrhythmia, and convulsions. Conversely, Theo Filene reduces serum levels of a throw my scene.
Recommended and white prescribing erythromycin

Question 20

Antibiotics, especially erythromycin, clarithromycin and tetracycline and digoxin (Lanoxin)

Answer 20

Congestive heart failure
It alters the G.I. flora and retard metabolism of digoxin, resulting in high dangerously high digoxin serum levels that may persist for several weeks after the discontinuation of the antibiotic patient Miss show signs of digitalis toxicity that is celebration wish you a disturbance at arrhythmias during the antibiotic therapy
Recommended should have digoxin levels monitored during the antibiotic therapy

Question 21

Antibiotics, cephalosporins, erythromycin, Clarithromycin and metronidazole and warfarin Coumadin

Answer 21

Atrial fibrillation, myocardial infarction, recent, postoperative major surgery, stroke prevention

Anticoagulant effect of warfarin may be increased by several antibiotic klasses, reduced synthesis of vitamin K by gut. Flora is a putative mechanism, but several antibiotics have antiplatelet an anticoagulant activity.
Monitor INR
Recommended, penicillin, tetracycline, and clindamycin would be preferred choices, but must be used with caution

Question 22

Acetaminophen and alcohol

Answer 22

Alcohol use and abuse

Acute alcohol is P450 inhibitor

Increased risk of liver toxicity, especially during fasting state, or a greater than or equal to 4 g of acetaminophen per day

Recommended : use lower doses of acetaminophen and encourage discontinuation of alcohol use

Question 23

Acetaminophen and warfarin (Coumadin)

Answer 23

Atrial fibrillation, thrombosis

Increased risk of bleeding if acetaminophen is given a dose of >than 2 gram / day for greater than 1 week.

Recommendation : limit, acetaminophen, dosing and duration, monitor INR

Question 24

Aspirin and oral hypoglycaemic (ex:sulphonylureas glyburide, chlorpropamide, aceto-hexamide

Answer 24

Diabetes type 2

Increased hypoglycaemic effect
Recommendation : avoid interaction

Question 25

Aspirin and other NSAIDS and anticoagulants (Coumarin)

Answer 25

Atrial fibrillation, myocardial, infarction, recent postoperative surgery, clot prevention

Increased risk of G.I. or oral bleeding
Recommendation : avoid interaction

Question 26

Aspirin and other NSAIDS and alcohol

Answer 26

Alcohol use and abuse

Increased risk of gastrointestinal bleeding

Recommendation : lower dose;encourage discontinuation of alcohol use

Question 27

Aspirin and diltiazem

Answer 27

Hypertension, angina
It is a ca channel blocker

Enhanced antiplatelet activity of aspirin

Recommendation : monitor for risk of prolonged, bleeding advise patient to notify physician or dentist if they experience unusual, bleeding or bruising

Question 28

NSAIDs and beta blockers/ ACE inhibitors

Answer 28

Hypertension, recent, myocardial infarction

Decrease antihypertensive effect

Recommendation : limited duration of NSAIDs dosage to about 4 days

Question 29

NSAIDs and lithium

Answer 29

Manic depression

Produces symptoms of lithium toxicity, including nausea, vomiting, slurred, speech, and mental confusion

Recommendatio : NSAIDs should not be prescribed to patients who take lithium. It can result in toxic levels of lithium or consult with the physician to reduce the lithium dose.

Question 30

NSAIDs naproxen and alendronate

Answer 30

It’s a Bhich phosphonate medication

Osteoporosis multiple myeloma

Recommendation or use acetaminophen products 

Question 31

NSAIDs and SSRIs )citalopram fluoxetine paroxetine sertraline )

Answer 31

Depression
Increased risk of peptic ulcers

Recommendation : avoid long-term use of NSAIDs use acetaminophen products instead

Question 32

NSAIDs and methotrexate

Answer 32

Connective, tissue disease, cancer therapy

Toxic levels of methotrexate may accumulate
Recommendation : avoid interaction if one high does MTX for cancer therapy
Low-dose MTX for arthritis is not a concern

Question 33

Meperidine and MAO inhibitors Ex: (isocarboxazid phenelzine)

Answer 33

Depressants (note, MAO inhibitors are often the last line of therapy)

May produce severe and potentially fatal, adverse excitatory, or depressive reactions

Recommen : avoid interaction

Question 34

Propoxyphene and carbamazepine

Answer 34

Trigeminal, neuralgia, seizure

Can significantly increase the plasma, concentration of carbamazepine

Recommendation: avoid interaction

Question 35

Lidocaine and Bhupivacaine

Answer 35

The additive effects of these two local anaesthetics increase the risk of central nervous system toxicity

recommendation: limit the dose of each

Question 36

Mapivacaine and meperidine( Demerol)

Answer 36

sedation with opioids may increase the risk of local anaesthetic toxicity, especially in children

recommendation: reduce the anaesthetic dose

Question 37

Barbiturates and digoxin Theo Filene, corticosteroid, oral anticoagulant(coumarin)

Answer 37

congestive heart failure, asthma, auto immune disease, atrial fibrillation

barbiturates bind P-450 cytochrome system in liver, and enhance the metabolism of many drugs thusreducing the effect of anticoagulants

recommendation :generally avoid: if necessary limit doors, and observe for adverse effects

Question 38

Barbiturates and benzodiazepines alcohol and anti-histamines

Answer 38

Anxiety, alcohol use and abuse, seasonal, allergies.

additive affects for sedation and respiratory depression

recommendation: reduce doors and administer combination of sedatives with extreme caution

Question 39

Benzodiazepines BZDp’s(example alprazolam, Chlordiazepoxide, diazepam triazolam) and cimetidine, oral contraceptives , fluoxetine, isoniazid , alcohol ,azoles antifungals like fluconazole itraconazole ketoconazole

Answer 39

peptic ulcer disease, depression, tuberculosis, alcohol use and abuse

delayed metabolism of BZDP increase the systemic exposure and pharmacologic effects. can result in excessive sedation and adverse psycho motor effects

recommendation reduce the dose of benzodiazepine or avoid interaction:

Question 40

benzodiazepines and digoxin (Lanoxin),, phenytoin, Theophylinne(theodur),

Answer 40

Congestive heart failure, epilepsy, asthma

Serum concentration of digoxin, and phenytoin may be increased, resulting in toxicity

antagonize sedative affects of benzodiazepine

recommendation: avoid interaction

Question 41

Benzodiazepines and protease inhibitors
( indicator, nelfinavir)

Answer 41

HIV infections and AIDS

Increase bio availability and effects of benzodiazepines, especially triazolam an oral mIDAZOLAM

Recommendation : avoid interaction

Question 42

epinephrin and Levonordefrine(neocobefrin) and nonselective beta blocker’s propanolol (Indaral), nadolol(corgard), penbutolol(elevator), pindolol (visken), sotalol, (beta pace), timolol(blocadren)

Answer 42

angina pectoris, hypertension, glaucoma, migraine, headache, hyperthyroidism, panic syndromes,

unopposed effects-increase blood pressure with secondary bradycardia

recommendation: initial dose is 1/2 cartridge containing 1:100000 Epinephrine; aspirate to avoid intravascular injection and inject slowly. monitor vital signs. If no adverse cardiovascular changes occur up to two cartridges containing a vasoconstrictor can be administered provide a five minute interval between the first and second cartridges and continual monitoring. Avoid Epinephrine containing retraction cords and higher concentration of epinephrine in the dental anesthetic.

Question 43

Epinephrine and levonordephrine(neocobefrin) and cocaine

Answer 43

illicit use,topical anaesthetic for mucous membrane procedures

blocks reuptake of norepinephrine and intensifies for synaptic response to epi-nephrinlike drugs. This potentiate the adrenergic effects on the heart with the potential for a heart attack recommendation recognizes signs and symptoms of cocaine abuse; avoid use of vasoconstrictors in these patients until cocaine has been withdrawn for at least 24 hours

Question 44

Epinephrine andlevonordephrine. And halothane

Answer 44

General anaesthetic for surgical procedures, stimulation of alpha and beta receptors, resulting in arrhythmia at the doses that exceed 2 µg per kilogram

recommendation: limit dose to remain below 2 µg per kilogram threshold. Aspirate to avoid intramuscular injection monitor the vital signs avoid Epinephrine containing retraction cord and concentration of epinephrin higher than 1:100000

Question 45

Epinephrine and levonordephrine and tricyclic antidepressants

Answer 45

depression, severe anxiety, neuropathic pain, attention, deficit disorder

blocks reuptake of norepinephrine, resulting in unopposed effects, increased pressor response (increase blood pressure, increase heart rate )—-and potential cardiac arrhythmias;effect is greater with Levonordephrine

recommendation: avoid levonordephrine..limit dose to 2 cartridges containing 1:100,000
epinephrine 36 µg.
aspirate to avoid intravascular injection monitor vital signs, avoid epinephrine containing retraction cord and higher concentration of epinephrin in the dental anaesthetic

Question 46

Metronidazole and warfarin

Answer 46

Metronidazole decreases the clearance of warfarin by 40%