PINDOLOL
Clinical safety rating: safe
Animal studies have demonstrated safety
Pindolol is a nonselective beta-adrenergic receptor antagonist with intrinsic sympathomimetic activity (ISA). It blocks beta-1 and beta-2 receptors, reducing heart rate, myocardial contractility, and blood pressure. Its ISA partially stimulates beta receptors, leading to less bradycardia and bronchoconstriction than other nonselective beta-blockers.
| Metabolism | Primarily hepatic via cytochrome P450 enzymes (CYP2D6) and conjugation with glucuronic acid; significant first-pass metabolism. Approximately 35-50% of the drug is excreted unchanged in urine. |
| Excretion | Pindolol is excreted primarily via the kidneys (renal clearance), with 60-65% of the dose eliminated unchanged in urine. Approximately 30-40% is metabolized in the liver, and biliary/fecal excretion accounts for less than 5%. |
| Half-life | The terminal elimination half-life of pindolol is 3-4 hours. However, due to its intrinsic sympathomimetic activity, the clinical duration of beta-blockade is longer, allowing for once-daily dosing in some patients. |
| Protein binding | Approximately 40% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Vd is 1.2-2.0 L/kg, indicating extensive extravascular distribution, including into tissues beyond the central compartment. |
| Bioavailability | Oral bioavailability is ~87% due to low first-pass hepatic metabolism. |
| Onset of Action | Oral: 30-60 minutes. Intravenous: 1-2 minutes. |
| Duration of Action | Oral: 12-24 hours, depending on dose and individual response; once-daily dosing is often sufficient due to ISA. Intravenous: 2-4 hours. |
5 mg orally twice daily, titrated to 10-60 mg/day in divided doses; maximum 60 mg/day.
| Dosage form | TABLET |
| Renal impairment | CrCl 10-50 mL/min: 50% of normal dose; CrCl <10 mL/min: 25% of normal dose. |
| Liver impairment | Child-Pugh Class A: no adjustment; Class B: reduce dose by 50%; Class C: avoid use or reduce by 75%. |
| Pediatric use | Hypertension: initially 0.1-0.2 mg/kg/dose orally twice daily, titrate up to 0.5-1 mg/kg/day divided every 12 hours; maximum 2 mg/kg/day or 60 mg/day. |
| Geriatric use | Start at 5 mg orally once daily, titrate slowly; lower doses often effective due to decreased clearance and increased sensitivity. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Other drugs that lower heart rate or blood pressure can have additive effects Abrupt withdrawal may exacerbate angina pectoris or cause myocardial infarction.
| Breastfeeding | Pindolol is excreted into breast milk in low amounts (M/P ratio approximately 0.8-1.0). The relative infant dose is estimated to be <5% of maternal weight-adjusted dose. No reported adverse effects in infants; use with caution, monitor for bradycardia and hypotension. |
| Teratogenic Risk | Pindolol is a beta-blocker. First trimester: limited human data, no consistent association with major malformations; animal studies show embryotoxicity at high doses. Second/third trimester: risk of fetal bradycardia, intrauterine growth restriction, hypoglycemia, and respiratory depression. Use only if benefit outweighs risk; avoid in preeclampsia due to potential fetal harm. |
■ FDA Black Box Warning
No FDA black box warning.
| Common Effects | Nausea Diarrhea Constipation Upset stomach Taste change Weakness Dizziness Headache Cold extremities Numbness of extremity Increased potassium level in blood Slow heart rate Decreased blood pressure |
| Serious Effects |
["Cardiogenic shock","Overt cardiac failure","Sinus bradycardia","Second- or third-degree AV block (unless pacemaker is present)","Bronchial asthma or severe COPD","Hypersensitivity to pindolol or any component of the formulation","Patients receiving MAO inhibitors (except MAO-B inhibitors)"]
| Precautions | ["Cardiac: may precipitate or exacerbate heart failure; avoid abrupt withdrawal (risk of myocardial ischemia, MI, or ventricular arrhythmias).","Bronchospasm: may cause bronchospasm in patients with asthma or COPD due to beta-2 blockade.","Peripheral vascular disease: may aggravate symptoms.","Hyperthyroidism: may mask signs of hyperthyroidism; abrupt withdrawal may precipitate thyroid storm.","Diabetes: may mask hypoglycemia symptoms (tachycardia); may potentiate insulin-induced hypoglycemia.","Renal impairment: use with caution; dose adjustment may be necessary.","Hepatic impairment: use with caution due to extensive hepatic metabolism."] |
Loading safety data…
| Fetal Monitoring | Monitor maternal heart rate, blood pressure, and symptoms of heart failure during therapy. Fetal monitoring: fetal heart rate and growth (ultrasound) during second and third trimesters; assess for intrauterine growth restriction. Neonatal monitoring: observe for bradycardia, hypoglycemia, and respiratory depression after delivery. |
| Fertility Effects | Limited data. Beta-blockers may impair male fertility by reducing sperm motility and count. In females, no known effects on fertility; theoretical risk of uterine blood flow reduction but not substantiated. |