Addiction Treatment Blog

Dependence

Before considering this in detail, we must exclude a type of physical dependence that occurs with a great number of drugs and ordinarily is of little consequence. Many drugs will cause rebound symptoms once they are discontinued. This happens particularly if they block receptors. This blockade leads to the blocked receptors becoming hypersensitive. When the blocking drug is then removed, these receptors are flooded with the normal neurotransmitter and they respond vigorously. It may take 48-72 hours for them to settle back down to normal.

Examples of this are the rebound phenomena that may occur with beta-blockers, such as propranolol, and the cholinergic rebound that may happen after stopping antidepressants with marked anticholinergic effects. Propranolol rebound may lead to palpitations, sweating and flushing. Cholinergic rebound may produce poor sleep and nausea or vomiting. These syndromes are not serious, and high doses of the relevant compounds are stopped abruptly. Read more…

Beta-blockers

In recent years, with concern over benzodiazepine use, there has been interest in the use of beta-blockers in the treatment of anxiety, principally propranolol (Inderal) and atenolol (Tenormin). Although they are used mainly in the treatment of hypertension, angina and cardiac arrhythmias, the rationale for their use in psychiatry is that they block the peripheral manifestations of anxiety, such as increased heart rate or shaking in the hands. Signs such as these are the cues we all use to judge, how anxious we are. When these effects of anxiety are controlled, it seems that two sets of feedback loops may be interrupted. Part of becoming anxious involves anxiety at signs of becoming anxious, such as increased heart rate and shaky hands. These manifestations of anxiety can lead to worries in their own right, for example, for the concert performer who may worry about both the audience and the effects of shaky hand on the violin bow. Similarly public speakers may have their nervousness faced with an audience augmented by nervousness about the effects of tremulous voice or a dry mouth on the act of speaking itself. Controlling effects such as heart rate, voice timbre and hand steadiness, therefore, can interrupt one feedback loop by taking away a set of stimuli to further anxiety. It can also interrupt another and ease the central anxiety by, as it were, removing the cues by which we all judge just how anxious we are. Read more…