Abiraterone Abiraterone (Abiraterone acetate) is a selective, irreversible inhibitor of the 17α‑hydroxylase/17,20‑lyase (CYP17) enzyme, used primarily for the management of metastatic castration‑resistant prostate cancer (mCRPC). — Mechanism of Action Inhibition of CYP17: Blocks 17α‑hydroxylase and 17,20‑lyase activities, halting production of androgens (testosterone, dihydrotestosterone) in the testes, adrenal glands, and prostate tumor tissue. Reduction of Androgenic … Read more
Abilify Abilify (generic name aripiprazole) is a second‑generation antipsychotic widely used in psychiatric practice. It functions as a partial agonist at dopamine D₂ receptors and 5‑HT₁A receptors, while acting as an antagonist at 5‑HT₂A receptors. Its unique profile allows effective treatment across a spectrum of neuropsychiatric disorders with a relatively favorable side‑effect profile. Mechanism of … Read more
Abecma Abecma (idecabtagene vicleucel) is a bispecific chimeric antigen receptor (CAR) T‑cell therapy engineered to target B‑cell maturation antigen (BCMA) on malignant plasma cells. It is approved for adults with relapsed or refractory multiple myeloma (RRMM) after at least three prior lines of therapy, including a proteasome inhibitor, immunomodulatory drug, and anti‑CD38 monoclonal antibody. — … Read more
Azithromycin Azithromycin is a macrolide antibiotic widely used for respiratory, skin, and sexually transmitted infections. It is known for its long half‑life and excellent tissue penetration, allowing short‑course regimens. — Mechanism of Action Azithromycin inhibits bacterial protein synthesis by reversible binding to the 50S ribosomal subunit. Blocks translocation, stalling the elongation step. Broadly active against … Read more
Azathioprine Mechanism of Action Azathioprine is a pro‑drug that is converted to 6‑mercaptopurine (6-MP). 6‑MP interferes with purine synthesis, inhibiting DNA and RNA synthesis in rapidly dividing immune cells. Conversion pathway: Azathioprine → 6-MP → active metabolites 6‑thioinosine monophosphate (6-TIMP) and 6‑thio-ATP. Immunosuppression: Blocks T‑cell proliferation and attenuates B‑cell‑mediated antibody production. Enzyme regulation: Thiopurine methyltransferase … Read more
Atorvastatin — Mechanism of Action Competitive inhibitor of HMG‑CoA reductase, the rate‑limiting enzyme of endogenous cholesterol biosynthesis in the liver. Down‑regulates hepatic LDL‑receptor transcription → ↑ LDL‑receptor density → enhanced LDL‑removal from plasma. Increases HDL‑cholesterol modestly by reducing hepatic triglyceride synthesis. Lowers VLDL production, thereby decreasing triglycerides. Secondary pleiotropic effects: improves endothelial function, reduces oxidative … Read more
Atomoxetine Atomoxetine (brand name Strattera®) is a selective norepinephrine reuptake inhibitor (NRI) approved primarily for the treatment of attention‑deficit/hyperactivity disorder (ADHD) in children, adolescents, and adults. Unlike stimulants, it does not produce euphoria or have a high abuse potential, making it a useful alternative for patients with contraindications or concerns regarding stimulant therapy. Mechanism of … Read more
Atenolol Atenolol is a selective β₁‑adrenergic receptor blocker commonly used for cardiovascular disorders. The drug’s low lipophilicity limits central nervous system penetration, making it a preferred choice when cognitive side‑effects are a concern. — Mechanism of Action Atenolol competitively antagonizes β₁‑adrenergic receptors in the myocardium, resulting in: ↓ Sympathetic stimulation → Reduced heart rate (negative … Read more
Aripiprazole Aripiprazole is a second‑generation antipsychotic distinguished by its partial agonist activity at dopamine D₂/D₃ receptors and serotonin 5‑HT₁A receptors, with antagonism at 5‑HT₂A. It is used extensively for schizophrenia, bipolar disorder, and adjunctive depression. Mechanism of Action Partial dopamine agonism at D₂/D₃: acts as a functional antagonist in hyperdopaminergic states (schizophrenia, mania) and as … Read more
Apixaban Apixaban is a direct oral anticoagulant (DOAC), widely recognized as a selective, reversible Factor Xa inhibitor used in thromboprophylaxis and antithrombotic therapy. Mechanism of Action Selective inhibition of activated Factor Xa → prevents conversion of prothrombin to thrombin. Binds both free Factor Xa and clot‑bound Factor Xa, ensuring sustained anticoagulation during clot formation. Does not inhibit thrombin … Read more