Term
| How are adverse drug reactions classified? |
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Definition
Type A - augmented pharmacologic effects (dose dependent and predictable)
Type B - idiosyncratic effects (dose independent and unpredictable)
Type C - chronic effects
Type D - delayed effects
Type E - end of Tx effects
Type F - failure of therapy |
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Term
| What is the difference btw On & Off-target adverse effects? |
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Definition
| The former binds to the intended receptor but at inappropriate conc. |
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Term
| On-Target effect can occur even when it reaches the intended receptor but? |
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Definition
| On non-target tissue, eg. Antihistamine diphenhydramine hydrochloride is a H1 receptor antagonist used to Tx allergic rxn, but it also crosses BBB to antagonize R's in CNS leading to somnolence (tiredness) thus cant drive with this drug |
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Term
| Give some examples of drug dosing errors and their effect? |
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Definition
| Anxiolytics (diazepam) -> sedation |
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Term
| Give an example of a drug acting on an unintended target? |
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Definition
| Terfenadine (an antihistamine), which also inhibits a cardiac potassium channel (hERG), which lead to fatal arrhythmias and thus withdrew |
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Term
| Enantiomers (mirror-image isomers) of a drug can cause off-target effects, examples include? |
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Definition
| Racemic thalidomide (both [R] and [S]-enantiomers) was used to Tx morning sickness. While [R] is an effective sedative, [S] is a potent teratogen |
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Term
| Give examples of unintended activation of different receptor subtypes? |
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Definition
Beta-1 adrenergic Rs are expressed in the heart and lead to increased HR and contraction
Beta-2 adrenergic Rs are mainly in the airways and SM cells and lead to relaxation & dilation
Beta-receptor antagonists (Beta-blockers) are often targeted to Beta-1 to help Tx angina or HF BUT some beta-blockers are not soo selective and thus give bronchoconstriction too |
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Term
| What are the two desired effects of acetaminophen? |
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Definition
| Analgesic (painkiller) & Antipyretic (reduce fever) |
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Term
| What are the two harmful immune responses of drugs? |
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Definition
A) Hypersensitivity (allergic) responses such as penicillin allergy or contact dermatitis
B) Autoimmune rxn - Methyldopa which causes hemolytic anemia by eliciting autoimmune rxn against Rh antigens |
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Term
| What is pharmacokinetics again? |
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Definition
| Its the absorption, distribution, metabolism and excretion of a drug |
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Term
| Examples of drugs that saturate or inhibit P450 enzymes are? |
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Definition
| Cimetidine, Ciprofloxacin, Ketoconazole, Clarithromycin, Quinidine & grapefruit juice |
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Term
| Drugs that induce P450 enzymes are? |
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Definition
| Rifampin, Phenobarbital, Dexamethasone, Carbamazepine and Tabacco |
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Term
| Give an example of a drug-drug interaction that leads to an exaggerated biological response? |
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Definition
A) Coadmin. of sildenafil (viagra) & nitroglycerin. The former inhibits PDE5 -> prolongs axn of cGMP, while the latter stimulates GC -> increases cGMP thus ultimately raising BP
B) Coadmin. of warfarin and heparin after surgery -> bleeding (NB that warfarin has a long T1/2 thus why Heparin is given IV to allow rapid Tx) |
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Term
| Explain the pharmacodynamics of two drug-herb interactions? |
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Definition
A) Ginkgo biloba inhibits platelet aggregation, it has the same effect as NSAIDs
B) SSRIs and St. John's wort together cause mild seratonergic syndrome (a neurological condition that results in fever, seizures & heart rhythm disturbances) |
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Term
| Explain two chronic effect of drug toxicity? |
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Definition
A) Dopamine receptor antagonists for schizophrenia can result in tardive dyskinesia (due to increased no. of receptors)
B) Hormone replacement therapy (HRT) can lead to endometrial CA (due to continued activation of estrogen receptors) |
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Term
| Name two drugs that cause pulmonary fibrosis? |
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Definition
| Amiodarone (antiarrhythmic) & Bleomycin (chemotherapeutic agent) |
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Term
| Cytotoxic alkylating agents (CA chemo) also damage normal RBC progenitors thus ...? |
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Definition
| Toxic to bone marrow -> AML |
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Term
| What is the difference btw carcinogenesis and teratogenesis? |
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Definition
| The former leads to CA while the latter leads to congenital malformations |
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Term
| Give two examples of teratogenesis? |
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Definition
| Retinoic acid (Vit. A), which is used to Tx acne. And thalidomide which was used for morning sickness. NB that organogenesis occurs btw 3rd-8th wk of gestation |
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Term
| FDA classification of drug use by pregnant women are? |
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Definition
A - Research done and no risk (includes methyldopa ???)
B - Animal studies have been done to show either no effect or adverse effect BUT studies on humans if available dont show any risk
C - Animal studies show adverse effects or are not done at all AND there are not human studies
D - Research shows risk to fetus but there is still utility
X - Not to be used at all (includes thalidomide and retinoic acid) |
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