Phenyltoloxamine


Phenyltoloxamine is an antihistamine with sedative and analgesic effects. It is available in combination with other drugs such as paracetamol.

Common use

Phenyltoloxamine is widely used in preparations as an enhancing agent for some analgesics and antitussives. It is widely used in certain parts of the world as cough suppressant usually with codeine, and sometimes by itself or in addition to dextromethorphan as it, like diphenhydramine, possesses antitussive action of its own and is particularly useful in semi-productive coughs because of its moderate drying action.
Phenyltoloxamine has analgesic and anti-spasmodic properties of its own and is used in combination with paracetamol, aspirin and other salicylates and other drugs in proprietary preparations available over the counter for backache, muscle strains and similar conditions. In this respect, it is similar to a closely related antihistamine, orphenadrine, and both drugs are very closely related to diphenhydramine and to doxylamine, the latter of which is the active ingredient in NyQuil and many other cough preparations.
Phenyltoloxamine is one of the more effective potentiators of codeine and derivatives such as ethylmorphine, dihydrocodeine, oxycodone, nicocodeine, hydrocodone and similar drugs like tramadol and propoxyphene for all indications, pain relief and cough suppression in particular.
Phenyltoloxamine, like diphenhydramine and doxylamine, is an effective non-narcotic anti-tussive on its own but tends to be effective only for productive coughs as the anticholinergic action will exacerbate dry, unproductive coughs, so it is often combined with dextromethorphan, codeine, ethylmorphine, dihydrocodeine, or hydrocodone in cough suppressants both over the counter and prescription.
It is also used to discourage abuse in certain opiate analgesics due to its unpleasant side effects at high doses. While therapeutic doses of phenyltoloxamine can generate mild to moderate euphoria as can many of its close chemical relatives, much higher doses have a side effect profile similar to that of atropine, which is also used in this fashion for tablets of diphenoxylate and morphine for oral administration.

Adverse effects

Common adverse effects are those associated with most anticholinergics, with effects being more pronounced in children and the elderly.

Availability

Though it is rare in several Western countries, phenyltoloxamine is widely used on the global scale, particularly in the developing world.
In the past it was not a controlled substance. It was taken off the market but is available OTC again in the US by some pharmaceutical companies. Some preparations contain opiates such as codeine or hydrocodone and are controlled. When used in preparations with acetaminophen it is generally over the counter.
Phenyltoloxamine combinations are sold under wide variety of preparations, brand names and dosages around the world: