Nitrates Apomorphine

APOMORPHINE NITRATES Risk of postural 1 BP when apomorphine is given with nitrates Additive effect apomorphine can cause postural 1 BP Monitor BP at least weekly until stable. Warn patients to report symptoms of hypotension (light-headedness, dizziness on standing, etc.)... 

The Husemann and Erdmann identification reactions for morphine and codeine in the DAB 9 (German Pharmacopoeia) involve the formation of the red-colored ortho-quinone (8) via apomorphine (5) under the influence of nitric acid with the simultaneous nitration of the benzene ring [15]. 

Demethylation of morphothebaine can be effected by heating with dilute hydrobromic acid at 170° C., the product being 6-hydroxyapo-morphine, which reduces silver nitrate very rapidly and is oxidized by atmospheric oxygen even more readily than apomorphine [16]. Morphothebaine and its dimethyl ether give dark green amorphous substances on oxidation with alcoholic iodine [5],... 

The hypotensive adverse effects of apomorphine may possibly be increased by nitrates, calcium-channel blockers and alpha blockers. There is some evidence that ACE inhibitors, beta blockers and diuretics do not increase the risk of hypotension. Nevertheless, caution is advised with all antihypertensives, and patients should be told about the symptoms of orthostatic hypotension and what to do should they occur. 

Apomorphine alone may cause postural hypotension, and this is potentially additive with the effects of vasoactive antihypertensives and nitrates. 

Fagan TC, Buttler S, Marbury T, Taylor A, Edmonds A and the SL APO study group. Cardiovascular safety of sublingual apomorphine in patients on stable doses of oral antihypertensive agents and nitrates. Am J Cardiol (2001) 88, 760-6. 

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