Drug Interactions and Adverse drug Reactions

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NARASARAOPETA INSTITUTE OF PHARMACEUTICAL SCIENCES

NARASARAOPETA INSTITUTE OF PHARMACEUTICAL SCIENCES 2

GUIDED BY:

Dr.J.N.SURESH KUMARM.PHARM.,Ph.D

PRINCIPAL&Professor`NARASAROPETA INSTITUTE OF PHARMACEUTICAL SCIENCES

PRESNTED BY :

RAGHAVENDRA KUMAR GUNDA

M.PHARM


DRUG:It is a chemical agent/Device intended for Diagnosis, cure, prevention, mitigation, treatment (or) therapy for a disorder/disease in human being and animal

DOSAGE FORM:It is defined as the combination of active drug component along with non drug moieties

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http://en.wikipedia.org/wiki/Image:La_Boqueria.JPG

Defining a Drug Interaction• “A measurable modification (in magnitude or

duration) of the action of one drug by prior or concomitant administration of another substance.”

• Drug-drug (Rx, OTC, herbal)• Drug-food• drug-alcohol• Drug-lab• drug-disease• drug-chemical


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Outcomes of drug interactions

1) Loss of therapeutic effect2) Toxicity3) Unexpected increase in pharmacological activity4) Beneficial effects e.g additive & potentiation (intended)

or antagonism (unintended).5) Chemical or physical interaction

e.g I.V incompatibility in fluid or syringes mixture


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1 in 107

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Lightning

Plane crash MurderAuto-cash

Fatal, unexpecteddrug reaction

Increasing risk of death



Drug Interactions

Pharmacodynamics The study of the action and effects of

medications on physiologic function Pharmacodynamic drug interactions

can be: Additive (two or more analgesics) Synergistic Antagonistic (dexamethasone and

glyburide)


Why doctors cannot keep drug interactions on mind?Too many informations: 2 700 drug interaction in CR,

where coincident therapy is forbidden by manufacturer

3 100 drug clinical relevant interactions in CR, where coincident therapy may cause serious damage to patient


REASONS / CAUSES OF DRUG INTERACTIONS

MULTIPLE DRUG THERAPY

MULTIPLE PRESCRIBERS

MULTIPLE PHARMACOLOGICAL EFFECTS OF

DRUG

MULTIPLE DISEASES

POOR PATIENT COMPLIANCE

ADVANCING AGE OF PATIENT

DRUG RELATED EFFECTS


Solution is to combine these activities: Education of doctors and pharmacists Cooperation of doctors and pharmacists to

identify high-risk patiens Feedback to doctors from databases of

health insurance funds Computer program:

alerts doctors when potential drug-drug interaction occurs

offers the most detailed evidence-based information in the actual time the prescription is written


Drug-drug interaction alert

Prescribing information and Patient information for paediatric medicines

Kalle Hoppu MD, PhDDirector, Poison Information Centre, Helsinki University Central HospitalDocent (Ass. professor) Dept.s of Paediatrics and Clinical Pharmacology, University of Helsinki, Helsinki, FinlandChairman, Sub-Committee for Paediatric Clinical Pharmacology, IUPHAR, Division of Clinical Pharmacology


Pharmacist Beware

A drug interaction can occur whenever a: New medication is started Medication is discontinued Dose is changed Drug is changed

Remember: Inducing interactions

Gradual onset/offset Inhibiting interactions

Quick onset/offset


The Role of a Pharmacist in Drug Interactions Pharmacists must be knowledgeable about

potential drug-drug, drug-food interactions Pharmacists should question a patient about

their current medications whenever filling a prescription that is new for them

Patients should be educated that drug interactions can also occur if they stop or receive a change in dose of their medications

Pharmacists should ask patients about their use of herbal preparations as they can interact with ARV therapy

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Drug-Food interactions

Grapefruit juice and Terfenadine Grapefruit juice and cyclosporin Grapefruit juice and felodipine Grapefruit contains : furanocoumarin compounds

that can selectively inhibit CYP3A4NARASARAOPETA INSTITUTE OF PHARMACEUTICAL SCIENCES

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SOME OTHER DRUG INTERACTIONS

TETRACYCLIN WITH MILKFOLICACID+ PHENYTOIN ANAEMIAORALCONTRACEPTIVES+B6,B12,Vit.C,FOLIC ACID DEFICIENCYMETOCLOPRAMIDE+DIGOXIN TOXICITY seALCOHOL+ANTIDIABETICS HYPO GLYCEMIA-BLOCKERS+ANTI DIABETICS need to reduce the ad doseAnti-Histaminics+ Alcohol Avoided ( Drowsiness)Acetaminophen+ Alcohol Severe Liver damageChronic Alcoholism (cocktile)+ NSAID stomach bleedingAlcohol+ Narcotic Analgesics severe side effects, coma, or deathBronchodilators( albuterol, theophylline)+ Food absorption DelayedCaptopril(ACEI)+ potassium supplements(bananas, oranges, green leafy vegetables) Hyperkalemia-BLOCKERS+FOOD changes in absorption (carvedilol shows decrease the chance Lower BP, DIURETIC +FOOD loss of the minerals, k+, ca+2, mg+2

Digoxin+candies, cakes and other sweets,FOOD Toxicity statins+Drink(Grape), food Toxicity


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Antiretroviral/Food InteractionsTake with food:

Lopinavir (capsules or solution): 50-130%

Saquinavir: 7 fold (fatty meal)

Nelfinavir: 2-3 fold

Ritonavir: 15% Itraconazole capsAtazanavir 70 % Ganciclovir up to

5%atovaquone 24%

Avoid food:Amprenavir: 23% with

high fat meal (regular food OK)

Indinavir: 77% with high fat meal (light snack OK)

ddI: 47% with mealEfavirenz: 79% high fat

meal increases toxicityRifampin: food may

levelsItraconazole liquidIsoniazidNARASARAOPETA INSTITUTE OF PHARMACEUTICAL

SCIENCES

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Avoid Antacids PIs

Indinavir (fos)amprenavir AmprenavirAtazanavir

Ketoconazole

FluoroquinolonesIsoniazidDapsoneZalcitabineDelavirdine


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Pharmaceutical Interactions

Interactions that occur prior to systemic administration.

For example incompatibility between two drugs mixed in an IV fluid. These interactions can be physical (e.g. with a visible precipitate) or chemical with no visible sign of a problem



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WHO Defines an ADVERSE DRUG REACTION as ”any noxious and unintended effects of drug which occur at doses normally used in the man for Prophylaxis, Diagnosis/Therapy of disease r for the modification of physiological functions ”How To Avoid ADR

DECREASE the rate of Parenteral AdministrationDecrease the frequency of administration by the use of prolonged action formulation Monitoring the blood level of toxic drugs particularly HEPATOTOXIC/NEPHROTOXIC


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DRUGS REMOVED FROM THE MARKET DURING THE 1990s

Source: J Clin Pharmacol 40:1093, 2000

DRUG CATEGORY REASONAstemizole antihistamine serious metabolic

drug intxnsBromfenac analgesic hepatotoxicityDexfenfluramine anorectic cardiovascular toxFelbamate anticonvulsant aplastic anemiaFlosequinan vasodilator increased mortalityGrepafloxacin antibiotic proarrhythmicMibefradil Ca channel blocker serious drug intxnsTemafloxacin antibiotic severe ADRTerfenadine antihistamine serious drug intxnTravafloxacin antibiotic hepatotoxicity


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CARCINOGENICANDROGENSESTROGENSORAL CONTRACEPTIVES

HEPATOTOXICISONIAZIDAMPHETAMINECHLORAMPHENICOLPAS

NEPHROTOXICCORTICOSTEROIDSALDOSTERONESALICYLATESFUROSEMIDE

DIABETOGENICNICOTINIC ACIDFUROSEMIDEASCORBIC ACID DERIVATIVES

TERATOGENIC AGENTSSTEROIDSCHLORAMPHEENICOLQUININEANTI DIABETICS(TOLBUTAMIDE)INSULINRESERPINETETRACYCLINANTI-HISTAMINESHEAVY METAL LIKE Hg, Pb, As


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SPECIAL THANKS TOSRI M.CHANDRASEKHARA RAO B . P H A R M . , M S C

DRUGS INSPECTOR, NARASARAOPET


Dr. J.N.SURESH KUMAR M . P H A R M . , P h . D

PRINCIPAL, NA RAS AR AO PETA IN S T IT UT E O F PH AR MACE UT IC AL S CI E NCE S ,

NARASARAOPET

SRI M.V.KOTESWARARAOCHAIRMAN,

NA RAS A RA OP ETA I N S TI TU TE OF PH AR MACE UTI C AL S CI EN CE S ,

NARASARAOPET

Dr. AJAY BABU CHM . P H A R M . , P h . D

HOD, DEPARTMENTOF PHARMACEUTICS NA RAS A RA OP ETA I N S TI TU TE OF PH AR MA CE UTI C AL

S CI E NCE S , NARASARAOPET

SRI P. VINAYKUMARM . P H A R MDy. DIRECTOR, DCA,GUNTUR


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MY SELF RAGHAVENDRA KUMAR GUNDA M.PHARM,ASSISTANT PROFESSOR, NARASARAOPETA INSTITUTE OF PHARMACEUTICAL SCIENCESMOBILE NO: +91-9666705894,E-MAIL ID: [email protected]

Health & Medicine

Drug Interactions and Adverse drug Reactions