Classifications: rauwolfia alkaloid; antihypertensive; Therapeutic: antihypertensive
Pregnancy Category: D
0.1 mg, 0.25 mg tablets
Principal alkaloid of Rauwolfia serpentina. Interferes with binding of serotonin at receptor sites, decreases synthesis of norepinephrine by depleting dopamine (its
precursor), and competitively inhibits their reuptake in storage granules. Depletes norepinephrine and serotonin in CNS,
peripheral nervous system, heart, and other organs and tissues.
Sympathetic inhibition seen in small but persistent decrease in BP, frequently associated with bradycardia, and reduced
cardiac output. Central effect results in tranquilization and sedation similar to those produced by chlorpromazine.
Mild essential hypertension and as adjunctive therapy with other antihypertensive agents in the more severe forms of hypertension.
Also used in agitated psychotic states, primarily in patients intolerant to phenothiazine or patients who also require antihypertensive
Reduce vasospastic attacks in Raynaud's phenomenon and other peripheral vascular disorders, and for short-term symptomatic
treatment of thyrotoxicosis.
Hypersensitivity to rauwolfia alkaloids; history of mental depression; acute peptic ulcer, ulcerative colitis; patients
receiving electroconvulsive therapy; within 714 d of MAO inhibitor therapy; pregnancy (category D), lactation. Safe
use in children is not established.
Renal insufficiency; cardiac arrhythmias; cardiac damage; cerebrovascular accident; history of peptic ulcers; epilepsy;
bronchitis, asthma; older adults, debilitated patients; gallstones; obesity; chronic sinusitis; parkinsonism; pheochromocytoma.
Route & Dosage
Adult: PO 0.5 mg/d initially, reduced to 0.10.25 mg/d
Geriatric: PO Start with 0.05 mg q.d., increase by 0.05 mg per wk
- Give with meals or with milk or other food to minimize possibility of gastric irritation (drug increases gastric secretions).
- Store in tight, light-resistant containers, preferably at 15°30° C (59°86° F), unless otherwise
directed by manufacturer.
Adverse Effects (≥1%)CNS: Drowsiness,
, nervousness, anxiety, nightmares, increased dreaming, headache, dizziness, increased appetite, dull
sensorium; prolonged use of large doses: CNS
stimulation (parkinsonian syndrome
): tremors, muscle rigidity; respiratory depression,
convulsions, hypothermia. CV:
orthostatic hypotension, increased AV conduction time (prolonged therapy); angina-like symptoms
, arrhythmias, CHF (rare). Special Senses: Nasal congestion,
epistaxis, lacrimation, blurred vision; miosis, ptosis, conjunctival congestion (acute toxicity
Dry mouth or excessive salivation, nausea, vomiting, abdominal cramps, diarrhea
, reactivation of peptic ulcer
heartburn, biliary colic. Hematologic:
Thrombocytopenic purpura, anemia
, prolonged BT. Body as a Whole:
Hypersensitivity (pruritus, rash, asthma), muscle aches, dysuria, fixed-drug eruptions. Urogenital:
Menstrual irregularities, breast engorgement, galactorrhea, gynecomastia, feminization (males), impaired sexual function,
Diagnostic Test Interference
Possibility of elevated blood glucose values; however, it is also reported that reserpine may decrease thiazide-induced hyperglycemia. Increase in serum prolactin with chronic administration of rauwolfia alkaloids; overdoses may cause initial increase in excretion of urinary catecholamines; decreases with chronic administration. Large doses may cause initial rise in urinary 5 HIAA excretion. Initial IM doses may increase urinary VMA excretion followed by decrease by end of third day of therapy (with oral or parenteral administration). Possible interference
with urinary steroid colorimetric determinations: 17-OHCS and 17-KS.
Interactions Drug: Diuretics,
other hypotensive agents
compound hypotensive effects; cardiac glycosides
) may increase risk of arrhythmias; mao inhibitors
may cause excitation and hypertension; cns depressants
compound depression; may decrease response to levodopa. Herbal: St. John's wort
may antagonize hypotensive effects.
2 h. Distribution:
Widely distributed, especially to adipose tissue
; crosses bloodbrain barrier and placenta; distributed in breast milk. Metabolism:
Extensively metabolized to inactive compounds. Elimination:
Slowly excreted, 60% in feces within 96 h and 10% in urine. Half-Life:
4.5 and 11.3 h.
Assessment & Drug Effects
- Assess vital signs at intervals prescribed by physician. Compare readings with baseline data and keep physician informed.
(Note: Drop in BP may be accompanied by bradycardia.)
- Lab tests: Periodic CBC with differential, platelet count, serum electrolytes, and plasma glucose.
- Supervise ambulation as indicated; postural hypotension occurs rarely with usual PO doses but is not uncommon in patients
receiving large parenteral doses.
- Monitor I&O, especially in patients with impaired kidney function. Report changes in I&O ratio and pattern.
- Full therapeutic effect of oral drug for hypertension may not occur until 23 wk of therapy, and effects may persist
for as long as 46 wk after drug is discontinued.
- Take special precautions with older adult and obese patients (half-life is reportedly prolonged in obese patients). Anticipate
increased incidence of adverse effects.
- Be aware that mental depression is a serious adverse effect and may be severe. It occurs most commonly in high dosage regimens
(e.g., 0.51 mg/d or more) and may not appear until 28 mo of therapy and may last for several months after drug
Patient & Family Education
- Take drug at the same time each day, do not skip or double doses, and do not stop therapy without advice of physician.
- Do not drive or engage in potentially hazardous activities until response to drug is known.
- Learn about possible adverse effects and report promptly to physician.
- Report the following possible beginning symptoms of depression: early morning insomnia, anorexia, inability to concentrate,
despondency, self-deprecation, attitude of detachment, mood swings, or impotence. Hospitalization may be necessary.
- Make position changes slowly, particularly from recumbent to upright posture, and lie down or sit down (head-low position)
if patient feels faint. Do not take hot showers or hot tub baths, and do not to stand still for prolonged periods. Report
symptoms of dizziness or light-headedness to physician.
- Check for edema and record weight daily to help make a distinction between weight gain from edema and that from increased
appetite. Consult physician about gain of 12 kg (35 lb) in 1 wk.
- Do not take OTC medications without consulting physician or pharmacist (many preparations for coughs and colds contain adrenergic
agents that affect the actions of rauwolfia alkaloids).