What is the interaction between Scopolamine and Cocaine?

From the Guidelines

Scopolamine and cocaine should never be used together due to the high risk of dangerous cardiovascular effects, severe anticholinergic symptoms, and potentially life-threatening complications. Scopolamine is a prescription anticholinergic medication used primarily to prevent motion sickness and to treat nausea and vomiting, working by blocking acetylcholine receptors in the central nervous system and vestibular apparatus 1. Cocaine, on the other hand, is a stimulant drug with high addiction potential, functioning by blocking the reuptake of neurotransmitters like dopamine and norepinephrine, creating euphoria and stimulation. The use of cocaine is associated with significant cardiovascular risks, including ventricular arrhythmias, ischemia, and myocardial infarction, as well as the potential for QT interval prolongation 1.

Key points to consider when evaluating the use of scopolamine and cocaine include:

• The potential for severe cardiovascular complications, including cardiac arrhythmias and myocardial infarction, associated with cocaine use 1
• The risk of anticholinergic symptoms, such as dry mouth, blurred vision, and urinary retention, associated with scopolamine use
• The potential for life-threatening complications, including respiratory depression and seizures, associated with the use of both substances
• The importance of avoiding the use of QT-prolonging medications, such as certain antipsychotics and antibiotics, in patients who have recently used cocaine 1

In terms of management, patients presenting with symptoms related to cocaine use, such as chest pain or cardiac arrhythmias, should be evaluated and treated promptly, with consideration given to the use of vasodilators, such as phentolamine or nitrates, to manage coronary vasospasm 1. Additionally, patients with suspected scopolamine toxicity should be monitored closely for signs of anticholinergic toxicity and treated supportively as needed. The use of scopolamine and cocaine together is strongly contraindicated due to the high risk of adverse effects, and alternative treatments should be sought for patients requiring management of motion sickness or other conditions for which scopolamine may be prescribed.

From the Research

Scopolamine and Cocaine Interaction

• Scopolamine is a nonselective muscarinic antagonist that produces both peripheral antimuscarinic properties and central sedative, antiemetic, and amnestic effects 2
• Cocaine is a psychomotor stimulant that interacts with muscarinic cholinergic receptors, which are targets for treating various psychiatric disorders 3
• The combination of cocaine and scopolamine has been shown to produce synergistic effects on locomotor activity in rats, suggesting that they stimulate locomotor activity through nonidentical pathways 4

Effects of Scopolamine on Cocaine-Induced Responses

• Scopolamine has been shown to inhibit cocaine-conditioned but not unconditioned stimulant effects in mice, suggesting that it impairs learning and memory associated with cocaine cues 5
• Scopolamine blocked cocaine-induced place-dependent hyperlocomotion (PDH) and conditioned place preference (CPP) in mice, supporting the hypothesis that cocaine cue reactivity is associated with learning and memory 5
• However, scopolamine had no effect on the induction and expression of cocaine-induced place-independent sensitization (PIS) in mice 5

Clinical Use of Scopolamine in Cocaine Addiction

• Some cocaine users have reported using scopolamine without medical supervision to reduce anxiety associated with cocaine withdrawal 6
• The use of scopolamine in cocaine abusers may be supported by a neurobiological and pharmacological point of view, but further research is needed to fully understand its effects 6