PTCB Practice Test 1 | Medications

Extended-release (XR, ER) tablets should not be crushed as it disrupts the controlled release, leading to potential toxicity.

Insulin glargine (Lantus) is a long-acting insulin that should never be mixed with other insulins, as it alters pH and reduces efficacy.

Levothyroxine should be taken on an empty stomach because food, especially calcium or iron, can interfere with absorption, reducing effectiveness.

Grapefruit juice inhibits CYP3A4, reducing simvastatin metabolism, increasing its blood levels and toxicity risk, leading to rhabdomyolysis and liver damage. Patients must avoid grapefruit products.

A black box warning is the strictest FDA warning, indicating severe or life-threatening risks associated with a medication, such as increased mortality or organ toxicity.

Warfarin is teratogenic and can cause birth defects if taken during pregnancy. Alternative anticoagulants like heparin are preferred.

Fluoroquinolones (e.g., ciprofloxacin) weaken connective tissue, increasing the risk of tendon rupture, especially in older adults.

Amoxicillin oral suspension is supplied as a dry powder and must be reconstituted with water before use.

Metoprolol, a beta-blocker, slows heart rate. A resting HR of 45 bpm suggests bradycardia. Dose reduction is necessary, but sudden withdrawal can cause rebound hypertension, so tapering is required.

Alprazolam (Xanax) is a benzodiazepine, used for anxiety and panic disorders. It enhances GABA neurotransmitter activity, producing a calming effect.

Aminoglycosides like gentamicin are nephrotoxic and ototoxic, requiring close renal monitoring. Toxicity causes kidney damage (reduced urine output) and hearing loss (tinnitus).

MAOIs block tyramine breakdown, leading to hypertensive crisis when consuming tyramine-rich foods (cheese, wine). Emergency treatment includes phentolamine or nifedipine.

Phenytoin (Dilantin) can precipitate when mixed with incompatible solutions. A 0.22-micron filter is needed to prevent crystallization in IV administration.

Trimethoprim-sulfamethoxazole inhibits CYP2C9, reducing warfarin metabolism, leading to increased INR and bleeding risk. Warfarin dose adjustments and INR monitoring are required when taking interacting antibiotics.

Naloxone is an opioid antagonist that rapidly reverses opioid overdoses by binding to opioid receptors, displacing opioids like fentanyl or heroin. It is administered intranasally or intravenously.

Insulin should be refrigerated (2-8°C) to maintain potency. Freezing or exposing insulin to direct sunlight can degrade its effectiveness.

Fentanyl patches must be rotated to prevent skin irritation. Heating pads increase drug absorption, leading to overdose risk. Patients must be educated on proper use.

Carbamazepine toxicity causes dizziness, drowsiness, and diplopia. Blood levels should be monitored to maintain a therapeutic range.

Heparin is primarily administered intravenously (IV) or subcutaneously for anticoagulation, as oral absorption is poor.

A lithium level > 2.0 mEq/L indicates severe toxicity. IV hydration enhances lithium excretion. Activated charcoal is ineffective as lithium is absorbed too quickly.

Fluoroquinolones (e.g., ciprofloxacin) can cause cartilage damage and should be avoided in children unless necessary.

Amiodarone-induced pulmonary toxicity presents as chronic cough or lung inflammation and can lead to fibrosis. The drug must be discontinued, and pulmonary function monitored.

Statins (e.g., atorvastatin, simvastatin) can cause muscle pain (myopathy) and, in rare cases, rhabdomyolysis, a severe breakdown of muscle tissue.

Spironolactone is a potassium-sparing diuretic, meaning it reduces potassium excretion, increasing hyperkalemia risk. Patients should limit potassium-rich foods like bananas and avocados.

Vitamin D supplements help maintain bone health and prevent deficiency-related conditions like osteoporosis.

Flumazenil is a benzodiazepine antagonist that rapidly reverses sedation and respiratory depression caused by benzodiazepine overdose.

Fentanyl patches require direct skin contact for absorption. Applying it to a hairy area can reduce effectiveness. The patch should be applied to clean, dry, non-irritated skin for optimal absorption.

IV phenytoin should not exceed 50 mg/min in adults. Rapid infusion can cause hypotension, CNS depression, and cardiac arrhythmias due to direct vasodilatory effects. Infusion must be slowed.

Paclitaxel (a chemotherapy agent) requires a test dose to check for anaphylactic reactions before full administration.

Spironolactone, a potassium-sparing diuretic, has anti-androgenic effects, leading to gynecomastia (breast enlargement) in males due to estrogenic activity.

Excipients are inactive substances that aid in tablet formation, improving stability, taste, or dissolution without contributing to the therapeutic effect.

USP <797> provides guidelines for sterile compounding to prevent contamination and ensure patient safety in injectable medication preparation.

Opioid analgesics slow gastrointestinal motility, leading to constipation, a major side effect requiring stool softeners or fiber intake.

Isoniazid (INH) depletes Vitamin B6 (pyridoxine), leading to peripheral neuropathy, which manifests as numbness and tingling. Supplementation is necessary.

Hypokalemia from furosemide increases digoxin toxicity risk, leading to nausea, arrhythmias, and confusion. Potassium levels must be monitored regularly.

Levothyroxine absorption is reduced by food, calcium, or iron supplements, leading to persistent hypothyroidism symptoms. It should be taken on an empty stomach for optimal effectiveness.

Light exposure can degrade certain medications, reducing their potency. Drugs like nitroglycerin must be stored in dark containers.

Levothyroxine absorption is reduced by calcium, iron, proton pump inhibitors, and food. It should be taken on an empty stomach with water and separate from other medications by at least 4 hours.

Nitroglycerin adsorbs to plastic IV tubing, reducing effectiveness. It must be stored and administered in glass bottles or special tubing.

The Cytochrome P450 enzyme system metabolizes many drugs. Inhibitors or inducers of CYP450 can alter drug levels significantly.

Extreme temperatures, humidity, and exposure to light can degrade medications, affecting their potency and stability.

Gentamicin, an aminoglycoside, causes irreversible ototoxicity by damaging the hair cells in the inner ear, leading to permanent hearing loss and balance issues. Monitoring drug levels is essential.

Vancomycin is primarily eliminated through the kidneys, so dose adjustments are necessary to prevent toxicity in patients with renal impairment.

Gemfibrozil increases statin levels, raising the risk of rhabdomyolysis. Myoglobin from muscle breakdown can damage the kidneys, causing dark urine.

ACE inhibitors (e.g., Lisinopril) are contraindicated in pregnancy due to their risk of fetal toxicity and developmental abnormalities.

Therapeutic equivalence means two drugs produce the same clinical effect and safety profile in patients when administered in the same dosage.

Methotrexate suppresses bone marrow, leading to leukopenia and infection risk. CBC monitoring is essential, and discontinuation may be required in cases of severe suppression.

Clozapine can cause agranulocytosis, leading to life-threatening infections. Monitoring ANC levels is essential to detect early leukopenia and prevent complicatio

Clozapine can cause agranulocytosis, a severe drop in neutrophils leading to infections. ANC levels should be checked, and the drug discontinued if dangerously low.

Rifampin induces CYP450 enzymes, increasing estrogen metabolism, reducing contraceptive effectiveness. Patients should use an alternative or additional contraceptive method.