Which of the following terms refers to the process through which a drug can increase the enzymes?
Summary The action of a drug depends on multiple factors. Pharmacokinetics is the study of a drug's movements in the body and can be described as what the body does to the drug, while pharmacodynamics is the study of a drug's action and effects on a body and can be described as what the drug does to the body. The administration of a drug in combination with other drugs or substances can cause a variety of interactions that can synergistically or antagonistically modify the effect of those drugs (e.g., via the activation or inhibition of cytochrome P450 enzymes by certain medications). Knowledge of interactions and pharmacokinetics help determine the ideal route of administration (topical, oral, IV). Drugs that are eliminated by the liver may attain high serum concentrations when hepatic function is impaired, which increases the risk of drug toxicity. The same principle applies to drugs that are eliminated via the kidneys. Show
OverviewBefore clinical trials begin, drugs are first tested in preclinical studies. Preclinical studies do not include human subjects. PharmacokineticsPharmacokinetics deals with drug absorption, distribution, metabolism, and excretion. Absorption (pharmacology)The process by which the drug reaches the bloodstream. The following factors affect drug absorption:
After the drug reaches the bloodstream, it is initially distributed in the most vascularized organs. Renal and liver disease can increase the apparent volume of distribution of drugs bound to plasma proteins. Types of drug kineticsIt takes zero PHEN-tAS-E (fantasy) to remember the drugs that are eliminated by zero-order kinetics: PHENytoin, ASpirin, Ethanol. Phases of biotransformationIn the elderly population, phase I reactions will usually become impaired before phase II reactions. Excretion (pharmacology)
Defects in renal, hepatic, or cardiac function can impair drug clearance. After 4 half-lives, more than 90% of the drug will be eliminated. Drugs and/or their metabolites are excreted from the body in one or more of the following ways:
LADME is an acronym for the important phases of pharmacokinetics: Liberation, Absorption, Distribution, Metabolism, Excretion. Loading doseMaintenance doseRenal or liver conditions lower the maintenance dose without affecting the loading dose. The main factor influencing the time to steady-state is t½, not dose or administration frequency. PharmacodynamicsPharmacodynamics deals with the effect of a drug at its site of action, the dose-response relationship of the drug, and the influence of other factors on the drug effect. Every functioning molecule in an organism is a potential site of action for a drug. Means through which drugs act include: Basic principlesAntagonists have zero efficacy, agonists have maximum efficacy, and partial agonists (see below) have submaximal efficacy. Types of drug-receptor interactions
Dose-response relationshipThe following terms are used to describe dose-response relationships:
TILE: Therapeutic Index = TD50/ED50 Drug tolerance and tachyphylaxisThe effect of a drug can decrease with repeated dosing:
PharmacogeneticsOverview
Examples of clinically relevant variations
Drug interactions and the cytochrome P450 systemDrug interactions
Types of interactionsCytochrome-P450 system
Carbamazepine acts as both substrate and inducer of CYP3A4. Rifampicin and carbamazepine are some of the strongest inducers of cytochrome P450 enzymes and can thus interact with many drugs.
P450 inducers: ↓ warfarin levels (Chronic Alcoholics Steal Phen-Phen and Never Refuse Greasy Carbs): C - Chronic alcohol use, S - St. John's wort, P - Phenytoin, P - Phenobarbital, N - Nevirapine, R - Rifampin, G - Griseofulvin, C - Carbamazepine P450 inhibitors can be remembered with “sickfaces.com group”: S - Sulfonamides, I - Isoniazid, C - Cimetidine, K - Ketoconazole, F - Fluconazole, A - Alcohol (binge drinking), C - Ciprofloxacin, E - Erythromycin, S - Sodium valproate, C - Chloramphenicol, O - Omeprazole, M - Metronidazole, G - Grapefruit juice The P450 substrates beta-BLOCKers, THEophylline, WARfarin, STATins, ORAL contraceptives, and antiPSYCHOtics: Let's BLOCK THE WAR between STATes with ORAL and PSYCHOlogical tools. Adverse effectsAdverse effects of substances can be classified into the following groups: We list the most important adverse effects. The selection is not exhaustive. Cardiovascular adverse effects
Dilated cardiomyopathy caused by Doxorubicin and Danurobicin can be prevented with Dexrazoxane. ABCDE to recall the 5 class of drugs potentially causing torsades de pointes: antiArrhythmic, antiBiotics, antiCychotics, antiDepressants and antiEmetics. Endocrine adverse effectsHydrochlorotiazide, Niacin, Tacrolimus and corticoSteroids can lead to High amouNT of Sugars in your blood. SUlfonamides, Lithium and AMiodarone may induce SUdden Lethargy And Myxedema (hypothyroidism). If patients taking Carbamazepine, Cyclophosphamide or SSRI get SIADH, they Can't Concentrate Serum Sodium! Gastrointestinal adverse effectsDiuretics, Alcohol, Corticosteroids, Valproic acid, Azathioprine and Didanosine are Drugs that Abrupty Cause Violent Abdominal Distress. Hematologic adverse effectsClozapine, Propylthiouracile, Methimazole, Carbamazepine, Ticlopidine, Dapsone, Colchicine, Chemotherapeutics and Gangiclovir Causes Pretty Major Collapse To Defense Cells Called Granulocytes (agranulocytosis). Carbamazepine, Methimazole, NSAIDs, Benzene, Chloramphenicol, Propylthiouracile Can't Make New Blood Cells Properly (aplastic anemia). MetHyldopa, Penicilline, and Cephalosporins may induce HeMolytic anemia (Positive Coombs test). YoU'RE Having a MEGA BLAST with Plays, Music, and Snacks! (HydroxyUREa, Phenytoin, Methotrexate and Sulfonamides may induce MEGAloBLASTic anemia) Musculoskeletal/skin/connective tissue adverse effectsMethyldopa, Phenytoin, Hydralazine, Isoniazid, Procainamide, Sulfonamides, Minocycline and Etanercept may provoke Malar rash, Painful HIPS, & Myalgia (Systemic Lupus Erythematous). Protease Inhibitors and Corticosteroids PICk your FAT somewhere else! Cyclosporine, CA2+ channel blockers, and Phenytoin can Cause Chubby Puffy Gums! Pyrazinamide, Furosemide, Niacin, Cyclosporine and Thiazides may induce Pain on your Feet, Needle-shaped Crystals, and Tophi (gout). With 5-FLuorouracil, Amiodarone, Sulfonamides & Tetracyclines you may geT sunburn in a FLASh (photosensitivity)! AntiEpiLEpTIC drugs, Penicillin, ALlopurinol and SULFonamides may provoke STEVE JOHNSON (syndrome), an EcLEcTIC PAL who loves SUrF! TETracyclines may discolor your TEeTh! Neurologic adverse effectsAntipsychotics, Reserpine, and Metoclopramide may make your ARMs rigid as in Parkinson's disease. Isoniazide, Bupropion, Imipenem/cilastatin, Tramadol and Enflurane lower seizures threshold (I BITE my tongue). Topiramate, Digoxin, Isoniazid, Ethambutol, Vigabatrin and PDE-5 inhibitors: These Drugs Induce Problems to Vision and Eyes! Multiorgan adverse effectsTo remember that Sulfonylureas, Cephalosporines, Metronidazole, Griseofulvin and Procarbazine can cause disulfiram-like reaction: Sorry, Can't Mess with Gin and Port wine. If you use Loop diuretics, Amphotericin B, cisPlatin, Vancomycin, or Aminoglycosides Listening And Peeing Vanish Away. Respiratory adverse effectsCArmustine, NiTrofurantoin, Busulfan, Amiodarone, Bleomycin, Methotrexate: I CAN'T Breathe Air Because of these Medications. Renal and genitourinary adverse effectsDiuretics, Penicillins, Sulfonamides, PPIs, NSAIDs and Rifampin may cause blooDy Pee, Sterile Pyuria, 'N' Rash (interstitial nephritis). Which of the following terms refers to the process through which a drug can increase the enzymes produced by the liver?Metabolic tolerance is one kind of tolerance and it takes place in the liver. Some drugs (like alcohol) cause enzyme induction – an increase in the enzymes produced by the liver.
When a drug bind with enzyme and increase IT activity is known as?Reversible inhibitors produce different types of inhibition depending on whether they bind to the enzyme, the enzyme-substrate complex, or both. Enzyme inhibitors play an important role in all cells, since they are generally specific to one enzyme and serve to control that enzyme's activity.
What does biotransformation mean?Biotransformation is a metabolic process that takes place mainly in the liver and helps to facilitate the excretion of both exogenous and endogenous substances. A series of reactions alter the chemical structures of these substances.
What is biotransformation of a drug?Biotransformation is a process by which organic compounds are transformed from one form to another, aided by organisms such as bacteria, fungi and enzymes. Biotransformations are used as a valuable strategy to build molecules, similar to parent drug in the drug discovery programme.
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