Frågan gäller eventuell interaktion mellan etanol och dexklorfeniramin. Bakgrunden är en/npatient s

Fråga: Frågan gäller eventuell interaktion mellan etanol och dexklorfeniramin. Bakgrunden är en patient som frågeställaren misstänker intar nämnda kombination i euforiserande syfte.

Sammanfattning: "Eventhough the most commonly reported interaction of antihistamines and alcohol is the

potentiation of the CNS depression, both chlorpheniramine and alcohol can be abused for

their ability to cause ""a high"". Chlorpheniramine belongs to alkylamines, a subgroup of

antihistamine that has less sedative and more stimulating effect on the CNS. Ethanol by it´s

depressive effect on the inhibitory control mechanisms can be percieved as a CNS stimulant.

It is well documented that antihistamines alone or in combination with other drugs have been

abused."

Svar: The misuse of antihistamines is well documented in the literature. Drugs in this category

are abused for their sedative action, for their hallucinogenic and CNS stimulating properties

(1-4). Chlorpheniramine belongs to the chemical class of antihistamines called alkylamines.

Among other differences, alkylamines cause less sedation and more CNS excitation and

hallucinations than the other chemical groups of antihistamines (5). Eventhough specific

cases of d-chlorpheniramine were not found (through Medline-search 1980-1985), there are

reports of abuse of other drugs from the same category. Jones et al (4) and Csillag and

Lendauer (3) reported abuse of pheniramine. More recently, the abuse of tripelennamine,

especially in combination with pentazocine has been wide-spread (6-9) in the USA.

Alcohol, eventhough pharmacologically a CNS depressant is viewed by many laymen as a

stimulant. The apparent stimulation results from the unrestrained activity of various parts of

the brain that have been freed from inhibition as a result of the depression of inhibitory

control mechanisms (10).

Thus your patient may use both of the mentioned drugs either together or separately to get "a

high".

Besides concidering the "CNS-stimulating" effects of chlorpheniramine and/or alcohol, it is

necessary to consider the consequences of the synergistic CNS depressant effects of these 2

drugs. In a study of 13 healthy volunteers Franks (11) showed that a single dose of

dexchlorpheniramine 4 mg/70 kg combined with ethanol 0.7 g/kg caused a significant

increase in sedation and in reaction time compared to ethanol alone or double placebo. Thus

if your patient is using high doses of either, or both drugs, the synergistic CNS-depressant

effect can result in an accident if he/she is engaged in an activity requiring concentration

and/or "normal" reaction time. However, with continuous use of the drugs tolerance to the

CNS depressant effects develops.