Cocaine induced myocardial ischaemia: nitrates versus benzodiazepines

Cocaine induced myocardial ischaemia: nitrates versus benzodiazepines

Report by Priya Bhangoo, SpR in Emergency Medicine

Checked by Andrew Parfitt and Tammy Wu, Consultants

St Thomas' Hospital, London, UK

Abstract

A short cut review was carried out to establish whether nitrates are better than benzodiazepines in the treatment of cocaine induced chest pain. Seven citations were reviewed of which two answered the three part question. The clinical bottom line is that in patients with cocaine induced chest pain it appears that nitrates or benzodiazepines are effective in combination or alone in resolving chest pain and improving cardiac performance. We recommend that the agent of choice may be influenced by the presence or absence of concurrent CNS symptoms.

Three part question

In [a cocaine user presenting to an emergency department with chest pain] are [nitrates superior to benzodiazepines] at [resolving chest pain]?

Clinical scenario

A 21 year old man attends the emergency department complaining of apparent cardiac chest pain. He has no risk factors for ischaemic heart disease but admits to recent cocaine abuse. His ECG appears ischaemic. You wonder how nitrates or diazepam, in combination or alone, compare at resolving chest pain and as regards clinical outcome.

Search strategy

Medline 1966 to February 2006 using the OVID interface: [{exp cocaine OR cocaine‐related disorders.mp.} AND {exp chest pain OR ischaemia OR angina OR acute coronary syndrome OR infarction.mp.} AND {exp diazepam OR exp benzodiazepines OR nitrates.mp.}].

Search outcome

Seven papers found of which two were relevant (table 1).

Table 1.

Author, date, country	Patient group	Study type	Outcomes	Key results	Study weaknesses
Honderick	27 patients attending ED,	Randomised	Pain score, chest	Mean pain score at 5 min	Convenience sample
et al,	chest pain <72 h duration.	prospective	pain severity	1.24 lower in NTG and	Sample size small
2003,	15 treated with NTG	single blind		lorazepam group (p<0.02)	No placebo arm for iv
USA	alone, 12 treated with NTG	control			lorazepam
	and lorazepam. NTG				Unusual therapeutic regimen
	group then crossed over				No follow up
Baumann	44 patients attending ED,	Randomised	Pain score, chest	No difference between either	Possibility of concomitant
et al,	all took cocaine within	control, double	pain severity	agent alone or in combination	coronary artery disease,
2000,	24 h (median 5 h	blind placebo 7	Haemodynamic	in terms of score reduction	anxieties regarding perception
USA	37 min) with history	control	performance and	When baseline differences adjusted,	symptomatology by cocaine
	suggestive of ischaemic		cardiac	statistical comparisons showed no	users, possibility of non‐
	chest pain, age 18–60		performance	demonstrable difference	ischaemic chest pain
	years

NTG, nitroglycerin.

Comment(s)

The demographics of both study populations are comparable to that of cocaine users attending the emergency department. The presenting electrocardiograms were largely normal in these patients. Treatment was based largely on history and symptoms. Nitrates were used sublingually. Diazepam was administered intravenously. Very small numbers and the lack of a placebo for lorazepam in the second paper may be responsible for the reduction in pain scores seen when patients received both agents.

Clinical bottom line

In patients with cocaine induced chest pain it appears that nitrates or benzodiazepines are effective in combination or alone in resolving chest pain and improving cardiac performance. We recommend that the agent of choice may be influenced by the presence or absence of concurrent CNS symptoms.