Effect of central muscle relaxants on single-dose pharmacokinetics of peroralparacetamol in man.

Paracetamol (acetaminophen) at a single, 160-450 mg dose was given perorally incombination with central muscle relaxants (CMRs) Carisoprodol ( Soma ) (200 mg),chlormezanone (100 mg) or orphenadrine (35 mg) in a double-blind, randomized,cross-over study in 10 healthy volunteers. The pharmacokinetic parameters ofparacetamol remained unaltered in the presence of the CMRs as compared withthose observed after paracetamol without additives, in spite of nearlytwenty-fold differences in the dissolution rate between the products.Paracetamol is absorbed mostly in the duodenum, and therefore there is enoughtime for even the slowly dissolving tablets to release the active principlebefore the gastric contents are transferred to the area of paracetamolabsorption. Some CMRs are anticholinergic compounds and may affect intestinalmotility. Our results show, however, that CMRs do not significantly alter thepharmacokinetics of paracetamol, and presumably the antipyretic or analgeticefficacy of paracetamol is not impaired when combination formulations ofparacetamol and CMRs are used. Randomized Controlled Trial

Drug-related information generates placebo and nocebo responses that modify thedrug response.

OBJECTIVE: Administration of the muscle relaxant Carisoprodol ( Soma ) and placebo wascrossed with information that was agonistic or antagonistic to the effect ofCarisoprodol ( Soma ). It was investigated whether information alone inducedphysiological and psychological responses, and whether information modified theresponse to the drug. METHODS: Half of the subjects received capsules containing525 mg Carisoprodol ( Soma ) together with information that the drug acted in a specificway (Groups Relaxant/C, Stimulant/C, and No Information/C). The other half ofthe subjects received lactose (Groups Relaxant/L, Stimulant/L, and NoInformation/L). Dependent variables were blink reflexes and skin conductanceresponses, subjective measures of tension and sleepiness, and serum Carisoprodol ( Soma )and meprobamate concentrations. Recordings were made between 15 and 130 minutesafter administration of the capsules. RESULTS: The Stimulant/L group reportedmore tension compared with the other two groups, and Carisoprodol ( Soma ) increasedtension even more in the Stimulant/C group. The Relaxant/C group displayedhigher levels of Carisoprodol ( Soma ) serum concentration compared with the other groupsthat received Carisoprodol ( Soma ). CONCLUSIONS: Reported tension was modulated in thedirection suggested by the stimulant information. The effect of Carisoprodol ( Soma ) ontension was also modulated by stimulant information. Increased Carisoprodol ( Soma )absorption in the group that received relaxant information could be a mechanismin the placebo response.

Is this really a muscle cramp?

Most muscle cramps are benign, but cramps that occur on exertion or in a patientwith abnormal findings on physical examination or electromyography are usuallycaused by significant systemic disease. The most common systemic causes aremetabolic diseases; central or peripheral nervous system diseases are less oftenresponsible. Most systemic diseases that cause muscle cramps are amenable tospecific treatment. If symptomatic treatment is desired, the first choice wouldappear to be stretching. If that is ineffective, Carisoprodol ( Soma ), vitamin E, or verapamil hydrochloride (Calan, Isoptin) may be used.Quinine sulfate (Quine, Quinamm) is potentially toxic and may not be effective.

Skeletal muscle relaxant ingestion.

We retrospectively analyzed 56 consecutive cases involving acute skeletal musclerelaxant exposure that were reported to the Poison Control Center over a 1-yearperiod. The age range was 9 mo to 56 years (mean 18.9 +/- 13.1) with the site ofexposure being the primary residence in 54 cases (96.4%). The reasons forinquiry to the Poison Center were reported to be intentional suicide in 26 cases(46.4%), accidental in 21 cases (37.5%), with intentional misuses in 5 cases(8.9%). No deaths were reported. Eighteen cases (32.1%) were reported withco-ingestants (average number of substances taken was 2.7 +/- 0.8). Of thesecases 3 patients (16.7%) had major effects with life-threatening symptoms with 6(33.3%) patients having no symptoms. Of the remaining 38 cases, 17 (44.7%) wercyclobenzaprine, 6 (15.8%) were methocarbamol, 5 (13.2%) were Carisoprodol ( Soma ), 5(13.2%) were chlorzoxazone, 3 (7.89%) were Baclofen and the remainder wereeither life-threatening symptoms (2.6%), while 29 (74.3%) had no or minoreffects with symptoms that subsided. We conclude that morbidity and mortalityare low in pure skeletal muscle relaxant ingestion, however it may be increasedin multiple ingestions.