Drug Interactions For Dental Professionals Flashcards
Antibiotics and contraceptives
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
B- lactams( penicillin and cephalosporin) + allopurinol (lopurin, zyloprim)
GOUT
Avoid ampicillin
Minor ALLERGY reaction to AMPICILLIN Other penicillins not implicated
B-lactams + beta blockers ( tenormin , lopressor ,inderal , corgard)
Clit
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
B-lactams+ tetracycline and other bacteriostatic antibiotics
Infection, acne or periodontal disease
Effectiveness of penicillin and cephalosporin is DECREASED by bacteriostatic agents.
Avoid interactions
Doxycycline and Methotrexate
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
Metronidazole and ethanol
Alcohol use or abuse
Severe DISULFIRAM like reaction
Avoid interaction
Metronidazole and lithium
MANIC DEPRESSION
Inhibits renal excretion of lithium.. so toxic levels of lithium reached. This causes confusion, ataxia, kidney damage
Avoid interaction
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
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
Tetracycline/ flouroquinolones and insulin
Diabetes Mellitus
Doxycycline and oxytetracycline ENHANCE the hypoglycaemic effect of exogenous administered insulin.
Recommended- select a different AB or increase carbohydrate intake
Antibiotics/antifungal’s metabolized by CYP three A4 and CYP1A2

Example macrolide antibiotics (erythromycin, clarithromycin)
Antifungal’s (ketoconazole, fluconazole)
Interacting with benzodiazepines
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
Antibiotics and antifungal’s with buspirone
Depression
Delayed metabolism of buspirone increasing pharmacological effect
Recommended: avoid interaction
Antibiotics and antifungal’s with carbamazepine (Tegretol)
Seizure disorder
Increase blood levels of carbamazepine leading to toxicity .
Symptoms include drowsiness, dizziness, nausea, headache, and blurred vision . Hospitalization required.
Recommended : avoid interactions
Antibiotics and antifungals with cisapride
Gastro-oesophageal reflex delayed metabolism of cisapride causes pharmacological effects and risk for cardiac arrhythmia and sudden death
Recommended avoid interaction
antibiotics and antifungals with cyclosporine
Organ transplantation, enhanced immunosuppression and nephrotoxicity recommended avoid interaction
I biotics and antifungal with disopyramide quinidine
Cardiac arrhythmias inhibits CYP three A4 metabolism, resulting in large increase an anti-arrhythmia drug that can lead to arrhythmias
recommended avoid interaction
Antibiotics and antifungals+ lovastatin, pravastatin, Simba, Staten, and other statins
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
I biotics and antifungal‘s+ Pimozide
Antipsychotic used to control motor actions
May result in increased concentration of by Musaid, and possibly prolongation of the QT interval
Recommended avoid interaction
Antibiotic and antifungal with prednisone or methylprednisolone
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
Antibiotic and antifungal+ Theo Filene(theodur)
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
Antibiotics, especially erythromycin, clarithromycin and tetracycline and digoxin (Lanoxin)
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
Antibiotics, cephalosporins, erythromycin, Clarithromycin and metronidazole and warfarin Coumadin
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
Acetaminophen and alcohol
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
Acetaminophen and warfarin (Coumadin)
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
Aspirin and oral hypoglycaemic (ex:sulphonylureas glyburide, chlorpropamide, aceto-hexamide
Diabetes type 2
Increased hypoglycaemic effect
Recommendation : avoid interaction
Aspirin and other NSAIDS and anticoagulants (Coumarin)
Atrial fibrillation, myocardial, infarction, recent postoperative surgery, clot prevention
Increased risk of G.I. or oral bleeding
Recommendation : avoid interaction
Aspirin and other NSAIDS and alcohol
Alcohol use and abuse
Increased risk of gastrointestinal bleeding
Recommendation : lower dose;encourage discontinuation of alcohol use
Aspirin and diltiazem
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
NSAIDs and beta blockers/ ACE inhibitors
Hypertension, recent, myocardial infarction
Decrease antihypertensive effect
Recommendation : limited duration of NSAIDs dosage to about 4 days
NSAIDs and lithium
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.
NSAIDs naproxen and alendronate
It’s a Bhich phosphonate medication
Osteoporosis multiple myeloma
Recommendation or use acetaminophen products 
NSAIDs and SSRIs )citalopram fluoxetine paroxetine sertraline )
Depression
Increased risk of peptic ulcers
Recommendation : avoid long-term use of NSAIDs use acetaminophen products instead
NSAIDs and methotrexate
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
Meperidine and MAO inhibitors Ex: (isocarboxazid phenelzine)
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
Propoxyphene and carbamazepine
Trigeminal, neuralgia, seizure
Can significantly increase the plasma, concentration of carbamazepine
Recommendation: avoid interaction
Lidocaine and Bhupivacaine
The additive effects of these two local anaesthetics increase the risk of central nervous system toxicity
recommendation: limit the dose of each
Mapivacaine and meperidine( Demerol)
sedation with opioids may increase the risk of local anaesthetic toxicity, especially in children
recommendation: reduce the anaesthetic dose
Barbiturates and digoxin Theo Filene, corticosteroid, oral anticoagulant(coumarin)
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
Barbiturates and benzodiazepines alcohol and anti-histamines
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
Benzodiazepines BZDp’s(example alprazolam, Chlordiazepoxide, diazepam triazolam) and cimetidine, oral contraceptives , fluoxetine, isoniazid , alcohol ,azoles antifungals like fluconazole itraconazole ketoconazole
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:
benzodiazepines and digoxin (Lanoxin),, phenytoin, Theophylinne(theodur),
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
Benzodiazepines and protease inhibitors
( indicator, nelfinavir)
HIV infections and AIDS
Increase bio availability and effects of benzodiazepines, especially triazolam an oral mIDAZOLAM
Recommendation : avoid interaction
epinephrin and Levonordefrine(neocobefrin) and nonselective beta blocker’s propanolol (Indaral), nadolol(corgard), penbutolol(elevator), pindolol (visken), sotalol, (beta pace), timolol(blocadren)
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.
Epinephrine and levonordephrine(neocobefrin) and cocaine
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
Epinephrine andlevonordephrine. And halothane
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
Epinephrine and levonordephrine and tricyclic antidepressants
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
Metronidazole and warfarin
Metronidazole decreases the clearance of warfarin by 40%
