VALSARTAN
Clinical safety rating: avoid
Contraindicated (not allowed)
Valsartan is an angiotensin II receptor antagonist (ARB) that selectively blocks the binding of angiotensin II to the AT1 receptor, resulting in vasodilation, reduced aldosterone secretion, and decreased blood pressure.
| Metabolism | Valsartan is primarily metabolized by CYP2C9 (minor pathways include CYP2C8 and CYP3A4). It undergoes glucuronidation via UGT1A3 and UGT2B7. |
| Excretion | Primarily eliminated unchanged in feces (83%) via biliary excretion, and approximately 13% in urine as unchanged drug. Renal clearance accounts for ~30% of total clearance. |
| Half-life | Terminal elimination half-life is approximately 6 hours (range 4–9 hours) in healthy adults. In patients with hepatic impairment, half-life is similar due to lack of significant metabolism. |
| Protein binding | 94–97% bound, primarily to serum albumin. |
| Volume of Distribution | Volume of distribution at steady state is approximately 17 L (0.23 L/kg). This indicates limited extravascular distribution, consistent with high protein binding. |
| Bioavailability | Oral bioavailability is about 25% (range 10–35%). Food decreases absorption and reduces peak concentration by about 50% but does not affect AUC significantly. |
| Onset of Action | Oral: 2 hours for peak serum concentration; antihypertensive effect begins within 2 weeks of therapy, but maximal effect may require 4 weeks. |
| Duration of Action | Duration of antihypertensive effect is 24 hours with once-daily dosing. Blood pressure reduction is sustained over the dosing interval, with a trough-to-peak ratio of 60–70%. |
| Molecular Weight | 435.52 |
80-320 mg orally once daily; initial dose typically 80 mg or 160 mg once daily.
| Dosage form | TABLET |
| Renal impairment | No adjustment for GFR ≥30 mL/min; for GFR <30 mL/min, caution and consider lower starting dose (e.g., 80 mg once daily) due to limited data; not dialyzable. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: caution, consider starting dose of 80 mg once daily; Child-Pugh Class C: not recommended due to lack of data. |
| Pediatric use | Children 6-16 years: starting dose 1.3 mg/kg (up to 40 mg) orally once daily, titrate to maximum 2.7 mg/kg (up to 160 mg) once daily. Children 1-5 years: starting dose 0.4 mg/kg (up to 20 mg) once daily, titrate to maximum 1.0 mg/kg (up to 80 mg) once daily. |
| Geriatric use | No specific dose adjustment; initiate at lower end of dosing range (80 mg once daily) due to potential for decreased renal function and increased sensitivity; monitor blood pressure and renal function. |
| 1st trimester | Avoid in first trimester unless no alternative; associated with increased risk of major congenital malformations, particularly cardiac and CNS defects. |
| 2nd trimester | Contraindicated in second trimester due to risk of fetal renal dysfunction, oligohydramnios, and pulmonary hypoplasia. |
| 3rd trimester | Contraindicated in third trimester due to confirmed fetal and neonatal toxicity including renal failure, skull ossification defects, and hypotension. |
Clinical note
NSAIDs may diminish the antihypertensive effect Lithium levels may be increased Use in pregnancy can cause injury and death to the developing fetus.
| Placental transfer | Crosses placenta in humans; detected in fetal plasma at concentrations 50-100% of maternal levels. |
| Breastfeeding | Transfer into breast milk is minimal; however, due to potential for adverse effects on neonatal renal function, caution is advised. Use only if clearly needed. |
■ FDA Black Box Warning
Fetal toxicity: Drugs acting directly on the renin-angiotensin system can cause injury and death to the developing fetus. Discontinue as soon as possible when pregnancy is detected.
| Common Effects | heart failure |
| Serious Effects |
Pregnancy (especially second and third trimesters)History of angioedema with prior ACE inhibitor or ARB therapyConcomitant use with aliskiren in patients with diabetes mellitus
| Precautions | Hypotension in volume- or salt-depleted patients, Worsening renal function, especially in patients with renal artery stenosis, Hyperkalemia, particularly with concurrent use of potassium-sparing diuretics or supplements, Angioedema, Hepatic impairment |
| Food/Dietary | Avoid high-potassium foods (e.g., bananas, oranges, tomatoes) if on concurrent K-sparing diuretics or with renal impairment. No significant interactions with other foods. |
Loading safety data…
| Lactation Rating | L3 - Moderately Safe |
| Teratogenic Risk | First trimester: Limited human data, but potential risk of renal and cardiac malformations based on animal studies and angiotensin II receptor blocker (ARB) class effects. Second and third trimesters: Fetal oligohydramnios, renal injury (including renal failure), skull ossification defects, limb contractures, hypotension, and neonatal death. Avoid use in pregnancy. |
| Fetal Monitoring | Serial fetal ultrasound (every 4-6 weeks) to assess amniotic fluid volume and fetal growth; fetal kidney function and anatomy assessment; neonatal blood pressure and renal function monitoring at birth. |
| Fertility Effects | No human data; animal studies show no significant effects on fertility at therapeutic doses. |
| Clinical Pearls | Valsartan is an angiotensin II receptor blocker (ARB) used for hypertension, heart failure, and post-MI. Monitor renal function and potassium; avoid in pregnancy. May cause angioedema. Dose adjustment needed in hepatic impairment. Combine with thiazide diuretics if response insufficient. |
| Patient Advice | Take exactly as prescribed, usually once daily. · Avoid potassium supplements or salt substitutes containing potassium. · Report swelling of face, lips, or throat immediately. · Use contraception and notify doctor if pregnant or planning pregnancy. · May cause dizziness; avoid driving until effects known. |