Action And Clinical Pharmacology: Yohimbine blocks presynaptic alpha-2 adrenergic receptors. Its action on peripheral blood vessels resembles that of reserpine, though it is weaker and of short duration. Yohimbine’s peripheral autonomic nervous system effect is to increase parasympathetic (cholinergic) and decrease sympathetic (adrenergic) activity. Yohimbine exerts a stimulating action on the mood and may increase anxiety. Such actions have not been adequately studied or related to dosage although they appear to require high doses of the drug. Yohimbine has a mild antidiuretic action, probably via stimulation of hypothalamic centres and release of posterior pituitary hormone. Reportedly, yohimbine exerts no significant influence on cardiac stimulation and other effects mediated by b-adrenergic receptors, its effect on blood pressure, if any, would be to lower it; however, no adequate studies are at hand to quantitate this effect in terms of yohimbine dosage.
Yohimbine is a 3a-15a-20b-17a-hydroxy yohimbine-16a-carboxylic acid methyl ester. The alkaloid is found in Rubaceae and related trees. Also in Rauwolfia Serpentina (L) Benth. Yohimbine is an indolalkylamine alkaloid with chemical similarity to reserpine.
Indications And Clinical Uses: As an alpha-adrenergic blocking agent.
Contra-Indications: Renal diseases, and patients sensitive to the drug or its components. In view of the limited and inadequate information at hand, no precise tabulation can be offered of additional contraindications.
Manufacturers’ Warnings In Clinical States: Generally, this drug is not proposed for use in females and certainly must not be used during pregnancy. Neither is this drug proposed for use in pediatric, geriatric or cardio-renal patients with gastric or duodenal ulcer history. Nor should it be used in conjunction with mood-modifying drugs such as antidepressants, or in psychiatric patients in general.
Adverse Reactions: Yohimbine readily penetrates the CNS and produces a complex pattern of responses in lower doses than required to produce peripheral a-adrenergic blockade. These include, antidiuresis, a general picture of central excitation including elevation of blood pressure and heart rate increased motor activity, irritability and tremor. Sweating, nausea and vomiting are common after parenteral administration of the drug. Also dizziness, headache, skin flushing reported when used orally.
Dosage And Administration: As directed by physician.
2 mg: Adult dose male: 1 to 2 tablets 3 times a day. Occasional side effects reported with this dosage are nausea, dizziness or nervousness. In the event of side effects, dosage is to be reduced to 1/2 dosage 3 times a day or as directed by physician.
5.4 mg: Adult dose male: 1 tablet 3 times a day. Occasional side effects reported with this dosage are nausea, dizziness or nervousness. In the event of side effects, dosage is to be reduced to 1/2 tablet 3 times a day or a directed by physician.
Availability And Storage: 2 mg: Each round, powder blue, uncoated, scored, embossed tablet, engraved 0-2.0 mg contains: yohimbine HCl 2 mg. Nonmedicinal ingredients: cellulose, FD&C Blue #1, magnesium stearate and sodium starch glycolate. Gluten-, lactose- and tartrazine-free. Amber glass bottles of 100 and 500.
5.4 mg: Each oval, pink, uncoated, scored, embossed tablet, engraved 0-5.4 mg contains: yohimbine HCl 5.4 mg. Nonmedicinal ingredients: cellulose, FD&C Red #3, magnesium stearate and sodium starch glycolate. Gluten-, lactose- and tartrazine-free. Amber glass bottles of 100 and 500.
YOHIMBINE Odan Sympatholytic