USMLE High-Yield Systems & Pharmacology Review

48 vocabulary-style flashcards covering menstrual disorders, adrenal crisis, antiretroviral toxicities, fructose metabolism, drug contraindications in pregnancy, antiemetics, lipid-lowering agents, antipsychotic adverse effects, aspiration syndromes, and biotin-dependent enzymes.

Endometriosis

Ectopic endometrial tissue causing dysmenorrhea, pelvic pain, dyspareunia, and infertility.

Uterine Fibroids (Leiomyomas)

Benign smooth-muscle tumors producing heavy menses with clots, pelvic pain/heaviness, constipation or urinary frequency, and an enlarged, irregular uterus.

Adenomyosis

Endometrial tissue in the myometrium leading to dysmenorrhea, heavy menses, and a bulky, globular, tender uterus.

Endometrial Cancer/Hyperplasia

Malignant or premalignant endometrium presenting with irregular, intermenstrual, or post-menopausal bleeding; risk factors include obesity, nulliparity, and chronic anovulation.

Acute Adrenal Crisis – Etiology

Triggered by adrenal hemorrhage/infarction or stress (illness, injury, surgery) in chronic adrenal-insufficient or long-term steroid patients.

Acute Adrenal Crisis – Clinical Features

Hypotension or shock, nausea/vomiting, abdominal pain, weakness, and fever.

Acute Adrenal Crisis – Treatment

Immediate IV hydrocortisone or dexamethasone plus high-flow intravenous fluids.

Nucleoside/Nucleotide Reverse Transcriptase Inhibitors (NRTIs)

Antiretroviral class (e.g., abacavir, tenofovir, zidovudine) associated with lactic acidosis as a class effect.

Abacavir – Adverse Effect

HLA-B*57:01–mediated hypersensitivity reaction (fever, rash, GI & respiratory symptoms).

Didanosine – Adverse Effect

Dose-related pancreatitis.

Zidovudine – Adverse Effect

Bone-marrow suppression leading to anemia or neutropenia.

Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs)

Efavirenz, nevirapine; class adverse effects include rash (SJS) and hepatotoxicity.

Efavirenz – Unique Toxicity

Vivid dreams, depression, dizziness (neuropsychiatric) and teratogenicity.

Protease Inhibitors (PIs)

Atazanavir, darunavir, indinavir, ritonavir; cause metabolic complications (lipodystrophy, dyslipidemia, insulin resistance).

Integrase Strand Transfer Inhibitors (INSTIs)

Dolutegravir, raltegravir; adverse effect: myopathy or ↑CK.

Aldolase B

Splits fructose-1-phosphate into DHAP and glyceraldehyde; deficiency causes hereditary fructose intolerance.

Tetracyclines in Pregnancy

Contraindicated due to permanent fetal teeth discoloration and bone growth inhibition.

Chloramphenicol in Pregnancy

Causes “gray baby” syndrome (cyanosis, hypotension) from immature hepatic glucuronidation.

Trimethoprim-Sulfamethoxazole in Pregnancy

Risk of folate antagonism leading to neural tube defects.

Aminoglycosides in Pregnancy

Fetal ototoxicity and vestibulotoxicity.

Scopolamine

Antimuscarinic patch used for motion sickness prevention.

Antihistamine Antiemetics

Diphenhydramine, meclizine, promethazine; promethazine useful for hyperemesis gravidarum.

Dopamine Receptor Antagonist Antiemetics

Prochlorperazine, metoclopramide; block D₂ receptors to relieve nausea.

5-HT₃ Receptor Antagonists

Ondansetron, granisetron; first line for chemotherapy-induced vomiting.

NK₁ Receptor Antagonists

Aprepitant, fosaprepitant; prevent delayed chemotherapy-induced emesis.

Statins

Inhibit HMG-CoA reductase → major ↓LDL; side effects: hepatotoxicity, myopathy.

Ezetimibe

Blocks intestinal cholesterol absorption, lowering LDL; may raise hepatotoxicity with statins.

Bile Acid Sequestrants

Cholestyramine, colestipol: prevent bile-acid reabsorption to lower LDL; cause GI upset & impair fat-soluble vitamin/drug absorption.

Niacin (Vitamin B3)

↓VLDL synthesis & ↑HDL; causes flushing/pruritus, hepatotoxicity, and hyperuricemia/gout.

Fibrates

Activate PPAR-α → large ↓triglycerides, ↑HDL; adverse: myopathy (worse with statins), gallstones.

Fish Oil / ω-3 Fatty Acids

↓VLDL & apolipoprotein B synthesis → lower triglycerides; side effect: fishy aftertaste.

Extrapyramidal Side Effects (EPS)

Acute dystonia, akathisia, and drug-induced parkinsonism from dopamine-blocker antipsychotics.

Tardive Dyskinesia

Late, involuntary oral-facial or choreiform movements after chronic antipsychotic use.

Neuroleptic Malignant Syndrome

Life-threatening fever, rigidity, autonomic instability, and altered mental status with antipsychotics.

Aspiration Pneumonia

Anaerobic lung infection occurring days after aspiration; treated with clindamycin or β-lactam/β-lactamase inhibitor.

Aspiration Pneumonitis

Chemical lung injury hours after gastric content aspiration; managed supportively without antibiotics.

Biotin (Vitamin B7)

Cofactor for carboxylase enzymes in gluconeogenesis, fatty-acid synthesis, and odd-chain fatty-acid oxidation.

Pyruvate Carboxylase

Biotin-dependent enzyme converting pyruvate → oxaloacetate in gluconeogenesis.

Acetyl-CoA Carboxylase

Biotin-dependent enzyme converting acetyl-CoA → malonyl-CoA for fatty-acid synthesis.

Propionyl-CoA Carboxylase

Biotin-dependent enzyme converting propionyl-CoA → methylmalonyl-CoA in odd-chain fatty-acid metabolism.