HYDROSERPINE PLUS (R-H-H)
Clinical safety rating
cautionComprehensive clinical and safety monograph for HYDROSERPINE PLUS (R-H-H) (HYDROSERPINE PLUS (R-H-H)).
Hydrochlorothiazide inhibits the sodium-chloride symporter in the distal convoluted tubule, increasing excretion of sodium, chloride, and water. Reserpine depletes catecholamines from peripheral sympathetic nerve endings, reducing sympathetic tone. Hydralazine directly relaxes arteriolar smooth muscle, decreasing systemic vascular resistance.
| Metabolism | Hydrochlorothiazide: Not metabolized, excreted unchanged in urine. Reserpine: Metabolized in the liver via hydrolysis and conjugation. Hydralazine: Acetylation in the liver via N-acetyltransferase (NAT2). |
| Excretion | Hydroflumethiazide: renal (50-65% unchanged); reserpine: renal (30%) and fecal (60%) as metabolites; hydralazine: renal (85% as metabolites, 10% unchanged). |
| Half-life | Hydroflumethiazide: 2-3 h; reserpine: 50-100 h (biphasic); hydralazine: 2-4 h (fast acetylators), 6-8 h (slow acetylators). |
| Protein binding | Hydroflumethiazide: 70% (albumin); reserpine: 96%; hydralazine: 87% (albumin and alpha-1 acid glycoprotein). |
| Volume of Distribution | Hydroflumethiazide: 3.6 L/kg; reserpine: 10-20 L/kg; hydralazine: 1.6 L/kg (central) and 2.7 L/kg (total). |
| Bioavailability | Oral: hydroflumethiazide 70-75%; reserpine 50-60%; hydralazine 30-50% (first-pass metabolism). |
| Onset of Action | Oral: hydroflumethiazide 2 h; reserpine 3-6 days; hydralazine 45-60 min. |
| Duration of Action | Hydroflumethiazide: 6-12 h; reserpine: 1-6 weeks; hydralazine: 2-6 h (dose-dependent). |
| Molecular Weight | Reserpine: 608.68 Da; Hydrochlorothiazide: 297.74 Da; Hydralazine: 160.18 Da |
1 tablet orally twice daily. Each tablet contains hydrochlorothiazide 25 mg, reserpine 0.125 mg, and hydralazine hydrochloride 25 mg.
| Dosage form | TABLET |
| Renal impairment | Contraindicated in severe renal impairment (CrCl <30 mL/min). For CrCl 30-50 mL/min: reduce dose to 1 tablet orally once daily; monitor electrolytes. No adjustment needed for CrCl >50 mL/min. |
| Liver impairment | Contraindicated in severe hepatic impairment (Child-Pugh class C). For Child-Pugh class A or B: use with caution; reduce dose to 1 tablet orally once daily and monitor for encephalopathy. |
| Pediatric use | Not recommended for pediatric use due to lack of safety and efficacy data. |
| Geriatric use | Start with 1 tablet orally once daily; titrate slowly. Monitor for orthostatic hypotension, electrolyte imbalances, and CNS effects. Avoid use in patients with depression. |
| 1st trimester | Reserpine is associated with increased risk of congenital malformations, including neural tube defects, and should be avoided. Hydrochlorothiazide may cause fetal or neonatal jaundice, thrombocytopenia, and electrolyte disturbances. Hydralazine has been associated with maternal hypotension and fetal distress. Avoid in first trimester. |
| 2nd trimester | Use only if potential benefit justifies potential risk. Reserpine may cause neonatal respiratory depression and bradycardia. Hydrochlorothiazide can cause fetal electrolyte imbalances and decreased placental perfusion. Hydralazine may cause maternal hypotension. |
| 3rd trimester | Avoid due to risk of neonatal respiratory depression, bradycardia, and electrolyte disturbances from reserpine and hydrochlorothiazide. Hydralazine may cause maternal hypotension and fetal distress. |
Clinical note
Comprehensive clinical and safety monograph for HYDROSERPINE PLUS (R-H-H) (HYDROSERPINE PLUS (R-H-H)).
| Placental transfer | Reserpine crosses the placenta; detectable in fetal plasma. Hydrochlorothiazide crosses the placenta; achieves fetal serum levels similar to maternal. Hydralazine crosses the placenta; fetal concentrations are lower than maternal. |
| Breastfeeding | Reserpine is excreted in breast milk and may cause adverse effects in nursing infants, including nasal congestion, respiratory depression, and hypotonia. Hydrochlorothiazide and hydralazine are present in low amounts but may affect milk production or cause electrolyte disturbances. Use with caution. |
| Lactation Rating | L4 - Possibly Hazardous |
| Teratogenic Risk | First trimester: Hydrochlorothiazide is associated with an increased risk of neural tube defects and oral clefts; reserpine may cause respiratory distress; hydralazine is not teratogenic in animal studies. Second and third trimesters: Hydrochlorothiazide may cause fetal electrolyte disturbances and thrombocytopenia; reserpine may cause neonatal bradycardia and hypotension; hydralazine may cause fetal hypotension and reflex tachycardia. |
| Fetal Monitoring | Monitor maternal blood pressure, serum electrolytes (potassium, sodium), renal function, and uric acid; fetal growth and amniotic fluid volume via ultrasound; neonatal assessment for bradycardia, hypotension, and electrolyte imbalance after birth. |
| Fertility Effects | Hydrochlorothiazide may reduce libido and cause erectile dysfunction in males; reserpine may cause galactorrhea and menstrual irregularities; hydralazine has no known direct effect on fertility. Theoretical risk of reduced sperm motility due to antihypertensive effects. |
■ FDA Black Box Warning
Reserpine: May cause mental depression, especially in patients with a history of depression. Discontinue at first signs of depression.
| Serious Effects |
Hypersensitivity to any componentActive peptic ulcer diseaseUlcerative colitisElectroshock therapy (concurrent)Severe renal impairment (anuria)Severe hepatic impairmentSystemic lupus erythematosus (hydralazine)Tachycardia with heart failure (hydralazine)
| Precautions | Hydrochlorothiazide: Electrolyte imbalance, hyperglycemia, hyperuricemia, lupus exacerbation. Reserpine: Mental depression, peptic ulcer, bradycardia. Hydralazine: Drug-induced lupus, tachycardia, myocardial ischemia, peripheral neuritis. |
| Food/Dietary | Avoid excessive intake of potassium-rich foods (e.g., bananas, oranges, spinach) due to the potassium-sparing effect of the combination? Note: Actually HYDROSERPINE PLUS contains hydrochlorothiazide which is potassium-wasting; reserpine and hydralazine do not affect potassium significantly. Thus, potassium supplementation may be needed; monitor potassium levels. Limit sodium intake to control blood pressure. Avoid tyramine-rich foods (e.g., aged cheeses, cured meats) due to reserpine's potential to cause hypertensive crisis? Reserpine is not a MAOI, but caution with high-tyramine foods is advised. |
| Clinical Pearls | Hydralazine and hydrochlorothiazide can cause lupus-like syndrome; monitor for arthralgias, rash, and fever. Reserpine depletes catecholamines, leading to potential sedation and depression; use with caution in patients with history of mood disorders. Check serum potassium and uric acid levels due to thiazide component. |
| Patient Advice | Take this medication exactly as prescribed; do not skip doses or double up. · Rise slowly from sitting or lying down to prevent dizziness. · Avoid driving or operating machinery until you know how this drug affects you. · Report any unusual weight gain, swelling, or shortness of breath. · Contact your doctor if you experience joint pain, fever, or rash. · Do not stop taking this medicine abruptly; it may cause blood pressure to rise. · Limit alcohol consumption as it can increase dizziness and drowsiness. |
Loading safety data…