apomorphine

Chemical Properties

Alkaloid; white crystalline mass; turns green on exposure; weakly soluble in water.

Originator

Apomorphine hydrochloride,Nastech Pharmaceuticals Company, Inc.

Uses

To treat acute poisoning; in the diagnosis and treatment of parkinsonism; a weak sensitizer and a powerful emetic.

Definition

A derivative of mor- phine that is a dopamine D2 agonist.

Indications

Apomorphine (Uprima) is a short-acting central and peripheral dopamine receptor agonist that can elicit male sexual responses. Dopamine appears to have an important role in normal erectile function. Apomorphine is a D₁-like,D₂-like dopamine receptor agonist.Apomorphine is not a new drug, and it has been used with limited success in ameliorating the symptoms of Parkinson’s disease and to induce emesis. It is not orally active except for a special buccal formulation, but it can be given parenterally, usually subcutaneously. Apomorphine is rapidly cleared from the kidney because of its high lipid solubility, its large volume of distribution, and its rapid metabolism.

Manufacturing Process

2 Methods of producing of apomorphine
1. The apomorphine was obtained by dehydratation of morphine at heating to 120°C in the presence phosphoric acid and rendering of HCl gas over reaction mixture.
2. The morphine was converted to β-chloromorphine and then to dichlorodihydrodesoxymorphine at heating to 140°-150°C in the presence hydrochloric acid. Then apomorphine is obtained by dehydratation of dichlorodihydrodesoxymorphine.

brand name

Apokyn (Vernalis).

Therapeutic Function

Emetic, Expectorant, Hypnotic, Antiparkinsonian, Dopamine agonist

Synthesis Reference(s)

Journal of the American Chemical Society, 72, p. 494, 1950 DOI: 10.1021/ja01157a129

Hazard

Poison; central nervous system effects.

Clinical Use

Aside from sildenafil, apomorphine is one of the few orally active (buccal route) pharmacological agents used in the treatment of ED. Apomorphine stimulates penile erection in both normal men and in men who are impotent. Apomorphine can be the drug of choice in patients with coexisting benign prostatic hyperplasia (BPH), coronary artery disease, and hypertension.

Side effects

When formulated into a controlled release sublingual capsule, apomorphine becomes a very effective orally active drug representative of a new class of centrally acting drugs useful in the treatment of ED. It has a narrow range (2 to 6 mg) of effective doses for its erectogenic actions, with the higher doses being more effective in inducing erections.Apomorphine can cause nausea, emesis, drowsiness, and dizziness.

Safety Profile

Poison by ingestion,subcutaneous, intravenous, and intraperitoneal routes.Experimental reproductive effects. Central nervous systemeffects. A powerful emetic. A weak sensitizer and maycause contact dermatitis. When heated to decomposition itemits hig

Purification Methods

Crystallise R-apomorphine from CHCl3 and a little pet ether, also from Et2O with 1 mol of Et2O which it loses at 100o. It sublimes in a high vacuum. It is white but turns green in moist air or in alkaline solution. UV: max 336, 399 (98% EtOH). The di-O-methylether is an oil b 175o/high vacuum, whose picrate crystallises from MeOH and has m 140o (dec). The di-O-acetate crystallises from EtOAc/pet ether with m 127-128o, [] D -88o (c 1, 0.1 N HCl). The di-O-benzoyl derivative has m 156-158o (from EtOH) and []D +43.44o (c 3.3, CHCl3). [Pachorr et al. Chem Ber 35 4377 1902, Beilstein 21 H 246.] NARCOTIC.