AFK Quiz – Pharma

Exam tips: Drugs with a significant first-pass effect are extensively metabolized in the gut wall/liver before reaching systemic circulation, so less active drug gets into the blood → lower oral bioavailability.

Exam tip: Inhibiting 5-lipoxygenase reduces leukotriene production (potent bronchoconstrictors), improving airflow and reducing bronchospasm — that’s why these drugs help asthma control.

Exam tip: In porphyria, avoid porphyrinogenic sedatives (classically barbiturates); nitrous oxide/oxygen is generally considered safe and is easily titrated with rapid recovery for dental procedures.

Exam tip: Ketorolac is a short-term NSAID used for acute moderate–severe pain, often viewed as one of the most “opioid-like” NSAIDs in analgesic strength; it is more potent than codeine plain, which is considered as a weak painkiller.

Exam tip: Phenobarbital is a classic CYP450 enzyme inducer, so it can increase metabolism of many other drugs (reduced effect/shorter duration). Acute alcohol is more associated with inhibition, not induction.

Exam tip: Phase II = conjugation (e.g., glucuronidation, acetylation, sulfation) to make drugs more water-soluble for excretion. Hydroxylation is a classic Phase I (oxidation) reaction.

Exam tip: Amoxicillin is largely renally cleared; in severe renal impairment (e.g., GFR/CrCl <10 mL/min) dosing intervals are extended — commonly q24h — to prevent accumulation and toxicity.

Exam tip: Acetaminophen is widely considered a preferred/safe analgesic in breastfeeding because milk levels are low and infant adverse effects are rare; ibuprofen is also commonly used for more severe pain.

Exam tip: MRONJ risk is highest with high-potency IV antiresorptives used in oncology, especially IV zoledronate (more than oral agents like alendronate/risedronate). Denosumab also carries MRONJ risk, but it’s prescribed every 6 months.

Exam tip: For acute dental pain (including post-op pain), guidelines emphasize NSAIDs as first-line; ketorolac is a short-term option for more severe inflammatory pain when acetaminophen alone fails. An asthmatic patient who takes Ventolin, is considered mild intermittent asthma, and all NSAIDs, except ASA, can be prescribed safely.

Exam tip: Standard prescribing references cap naproxen at 1250 mg/day.

Exam tip: First generation antihistamines like chlorpheniramine have sedative properties and their concurrent use with opioids should be avoided due to the risk of oversedation.

Exam tip: Acetaminophen is first-line for mild–moderate post-extraction pain in elderly patients due to minimal drug interactions and safer cardiovascular profile (ADA pain management guidelines).

Exam tip: Thromboxane A₂ (TXA₂), produced by activated platelets, promotes platelet aggregation and vasoconstriction. In contrast, prostacyclin (PGI₂) causes vasodilation and inhibits platelet aggregation (AHA physiology references).

Exam tip: α-glucosidase inhibitors (miglitol, acarbose) delay carbohydrate absorption in the small intestine, reducing post-prandial hyperglycemia. They do not stimulate insulin release and have low hypoglycemia risk (ADA Standards of Care).

Exam tip: Furosemide blocks the Na⁺-K⁺-2Cl⁻ cotransporter in the thick ascending loop of Henle, causing potent diuresis. This reduces intravascular volume and blood pressure (ACC/AHA hypertension guidelines).

Exam tip: Glyburide (sulfonylurea) stimulates insulin release from pancreatic β-cells and enhances insulin sensitivity. It does not directly suppress hepatic gluconeogenesis (metformin does) (ADA pharmacology).

Exam tip: Sharp, stimulus-evoked pain progressing to prolonged ache is characteristic of neuropathic pain. Pregabalin is first-line for neuropathic pain due to calcium-channel modulation and central sensitization control (AAN guidelines).

Exam tip: Promethazine is a first-generation antihistamine with sedative and antiemetic properties. It has no anticonvulsant mechanism and may lower seizure threshold (FDA labeling).

Exam tip: Ibuprofen is a non-selective COX-1 and COX-2 inhibitor, reducing prostaglandin synthesis. This accounts for its analgesic, anti-inflammatory, and antipyretic effects (ADA pharmacology references).

Exam Tip: Neostigmine is an acetylcholinesterase inhibitor, increasing acetylcholine levels and stimulating salivary secretion. Anticholinergics (e.g., atropine) worsen xerostomia (ADA oral medicine guidelines).

EXAM TIP: Digoxin inhibits Na⁺/K⁺-ATPase, increasing intracellular calcium and myocardial contractility (positive inotrope)  Used in heart failure and atrial fibrillation (ACC/AHA cardiac guidelines).

EXAM TIP: NSAIDs inhibit COX, shunting arachidonic acid toward leukotriene production, which can trigger bronchospasm. This is a known risk in aspirin-exacerbated respiratory disease (GINA & AHA guidelines).

EXAM TIP: Unnecessary antibiotic prescribing is the primary driver of antimicrobial resistance. Inappropriate use promotes selective pressure and resistant strains (CDC, PHAC, ADA guidelines).

EXAM TIP: TMP-SMX inhibits CYP2C9, increasing warfarin levels and bleeding risk. This interaction is clinically significant and well documented (FDA & ACC guidelines).

EXAM TIP: Aging is associated with a progressive decline in renal mass and renal blood flow, leading to a reduced GFR, which affects drug clearance and increases toxicity risk in elderly patients; gastric pH increases (not decreases), hepatic enzyme activity declines, and GI motility slows with age.

EXAM TIP: Amitriptyline (a TCA) has prominent anticholinergic and CNS effects including xerostomia, constipation, confusion, and orthostatic hypotension; urinary retention, not increased urination, is characteristic due to antimuscarinic action.

EXAM TIP: Benzodiazepines such as diazepam can worsen acute narrow-angle glaucoma by increasing intraocular pressure and should be avoided despite their anxiolytic effect; non-benzodiazepine sedatives may be safer alternatives in this setting.

EXAM TIP: Diphenhydramine (Benadryl) causes CNS depression and anticholinergic effects, which are additive with opioids like meperidine, increasing the risk of respiratory depression and delirium; this interaction is clinically significant and avoidable.

EXAM TIP: Nitrous oxide is not absolutely contraindicated in the third trimester when used briefly with appropriate oxygenation; emphysema, otitis media, viral infections, and some neurodevelopmental disorders are contraindications due to air trapping or cooperation issues.

EXAM TIP: Class I antiarrhythmics such as quinidine suppress arrhythmias primarily by prolonging the cardiac action potential and refractory period, reducing abnormal impulse propagation rather than stimulating pacemakers or beta receptors.

EXAM TIP: Parasympathetic activation via vagal tone slows SA node depolarization, decreases heart rate, reduces AV conduction velocity, and lowers contractility; increased depolarization speed is a sympathetic effect, not parasympathetic.

EXAM TIP: Acetylsalicylic acid (aspirin) irreversibly inhibits platelet COX-1, prolonging bleeding time; it also provides antipyretic, anti-inflammatory effects and increases uric acid excretion at high doses while increasing GI bleeding risk.

EXAM TIP: IV pamidronate is used to inhibit osteoclast-mediated bone resorption in Paget’s disease, multiple myeloma, hypercalcemia of malignancy, and bone metastases, but osteopetrosis involves defective osteoclast function and is not an indication.

EXAM TIP: Thiopental, an ultrashort acting barbiturate, is rapidly redistributed from the brain into adipose tissue, terminating its anesthetic effect.

EXAM TIP: Cefaclor, like penicillin V, is a β-lactam antibiotic that inhibits bacterial cell wall synthesis by binding penicillin-binding proteins; the others act via protein synthesis or DNA replication inhibition.

EXAM TIP: Thiazide diuretics act on the distal convoluted tubule, inhibiting sodium-chloride reabsorption; loop diuretics act in the ascending loop, potassium-sparing agents act in the collecting duct, and mannitol works osmotically.

EXAM TIP: A MAC of 105% indicates that nitrous oxide cannot achieve surgical anesthesia alone, reflecting low anesthetic potency despite rapid onset and recovery; lower MAC values correspond to higher potency agents.

EXAM TIP: Zolpidem is considered relatively safer in pregnancy compared with benzodiazepines and older sedatives, as it has not shown consistent teratogenic effects when used short term; benzodiazepines (alprazolam, triazolam) are associated with fetal CNS depression and cleft risk, while chloral hydrate is generally avoided.

EXAM TIP: SSRIs such as sertraline inhibit platelet serotonin uptake, impairing platelet aggregation; when combined with NSAIDs like ibuprofen, this results in a synergistic increase in gastrointestinal bleeding risk, a well-documented interaction in clinical guidelines.

EXAM TIP: Benzodiazepines have a wider safety margin than barbiturates because they enhance GABA action without directly opening chloride channels, resulting in less respiratory depression and overdose risk compared with barbiturates.

EXAM TIP: Cimetidine inhibits hepatic CYP450 enzymes, reducing first-pass metabolism of propranolol and thereby doubling its oral bioavailability; rifampin and chronic alcohol induce enzymes and decrease drug levels.

EXAM TIP: The blood:gas solubility coefficient determines how quickly an inhalational anesthetic equilibrates between blood and alveoli; lower solubility leads to faster induction and recovery, while higher solubility slows onset.

EXAM TIP: Macrolides and clindamycin both inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit; macrolides are primarily bacteriostatic and are associated with QT prolongation, not shortening.

EXAM TIP: Diphenhydramine commonly causes tachycardia, not bradycardia, due to its antimuscarinic effects; sedation, antiemetic action, local anesthetic activity, and anticholinergic effects are all expected pharmacologic actions.

EXAM TIP: Staphylococcus aureus frequently produces β-lactamase, making it more resistant to amoxicillin compared with oral streptococci and anaerobes, which are generally more susceptible.

EXAM TIP: Famotidine is an H₂-receptor antagonist that directly reduces gastric acid secretion by inhibiting histamine-mediated stimulation of parietal cells; the other agents act by mucosal protection or neutralization.

EXAM TIP: NSAIDs are contraindicated in the third trimester due to risk of premature closure of the ductus arteriosus and oligohydramnios; clindamycin, chlorhexidine, and short-term opioids may be used cautiously if indicated.

EXAM TIP: Nitrous oxide is stored as a liquid–gas equilibrium, so tank pressure remains at approximately 750 psi until nearly empty; pressure does not reflect volume until the liquid phase is depleted.

EXAM TIP: Pilocarpine is a muscarinic agonist that stimulates salivary gland secretion and is FDA-approved for management of radiation-induced xerostomia; it directly addresses salivary hypofunction rather than acid or allergy pathways.