The influence of anticholinergic drug selection on the efficacy of antidotal treatment of soman-poisoned rats.

The influence of some anticholinergic drugs (atropine, benactyzine, biperiden, scopolamine) on the efficacy of antidotal treatment to eliminate soman (O-pinacolyl methylphosphonofluoridate)-induced disturbance of respiration and circulation and to protect experimental animals poisoned with supralethal dose of soman (1.5 x LD(50)) was investigated in a rat model with on-line monitoring of respiratory and circulatory parameters. While the oxime HI-6 in combination with atropine prevented soman-induced changes in monitored physiological parameters insufficiently and very shortly, the combination of HI-6 with benactyzine or biperiden is able to prevent soman-induced alteration of respiration and circulation much more longer. Nevertheless, only rats treated with HI-6 in combination with scopolamine were fully protected against the lethal toxic effects of soman within 2 h following soman challenge. Our findings confirm that anticholinergic drugs with the strong central antimuscarinic activity, such as benactyzine, biperiden and especially scopolamine, seem to be more effective adjuncts to HI-6 treatment of severe acute soman-induced poisoning than atropine.

The skier's nose: a model of cold-induced rhinorrhea.

Cold-induced rhinorrhea (CIR) is a commonly experienced discomfort not previously addressed in the medical literature. In a 2-part study, we assessed the prevalence and described the characteristics of CIR and evaluated the efficacy of an anticholinergic nasal spray in its treatment. In Part 1, 90 general medical patients at a ski resort clinic were asked to describe their symptoms associated with cold exposure. Ninety-six percent reported some degree of CIR; 48% reported moderate to severe CIR. Fifty percent had some degree of nasal congestion and 33% reported sneezing. Allergic and nonallergic patients described similar degrees of rhinorrhea. In Part 2, 14 ski patrollers were given atropine sulfate in saline (AS/S) nasal spray before cold exposure in double-blinded placebo (P) controlled crossover fashion. Ninety-two percent noted improvement of CIR with AS/S and 8% experienced no change. None of the subjects noted worsening of symptoms, however, one subject reported excessive dryness at the AS/S concentration used. All 14 subjects receiving P experienced no change in CIR. We conclude that CIR is a distinct clinical syndrome frequently seen with cold temperature exposure, presenting primarily as rhinorrhea and sometimes involving nasal congestion and sneezing. Pretreatment with a 0.005% solution AS/S can effectively block CIR with only minimal short-term side effects.

Physicochemical stability of a preanesthetic mixture of hydroxyzine hydrochloride and atropine sulfate.

The stability of a combination of hydroxyzine hydrochloride and atropine sulfate stored in syringes was studied. Syringes containing the two drugs were stored at 25 C and 3 C for ten days and analyzed at specific time intervals. Absorption spectra, chromatographic characteristics and pH were determined. Results showed the admixture to be stable for ten days at room temperature or under refrigeration. The technique used would probably not detect any significant degradation of atropine sulfate unless the reaction occurred with the hydroxyzine hydrochloride.