Plasma concentration measurements. The most useful complementary examination for PSE Investigation Is generally the monitoring of plasma concentratlons of suspected medications. Monitoring of drug concentration Is frequently performed for some drugs with high risk of toxicity, eg, digoxin, theophylline, or lidocaine. Many other compounds can also be dosed in specialized laboratories. If past analyses
were performed for a given patient, they may also provide valuable clues. This may apply even if different medications were measured. This occurs because an abnormally high concentration of a medication may suggest a weak or absent metabolic pathway, as discussed in the mechanisms section above. Knowledge of the patient’s deficiencies Inhibitors,research,lifescience,medical in metabolism
allows avoidance of some PSEs by future prescriptions. Genotyping is a complementary examination to detect polymorphisms Inhibitors,research,lifescience,medical of hepatic enzymes. Description of psychiatric side effects Table III 3,8,9,17-197 gives a list of medications that might induce depression, mania, anxiety, or psychotic syndromes (defined by delusions Inhibitors,research,lifescience,medical and/or hallucinations). This information is qualitative, in the sense that the severity or the frequency of these side effects under each medication or class is not indicated. Specific information can be found in the bibliography. Some psychotropics, such as benzodiazepines, are listed in Table III because they are frequently prescribed in internal medicine. Obviously, more than one of these PSEs can occur in a given patient. For example, many depressive states are accompanied by anxiety Some clinically relevant examples of medications Inhibitors,research,lifescience,medical presented In Table III are discussed below in more detail. Table III. Psychiatric side effects potentially induced by pharmacological treatment. Mefloquine and chloroquine Mefloquine, which is prescribed for the prophylaxis or treatment of malaria, frequently causes PSEs. These PSEs can be severe: psychosis, delusion, and even suicidal Inhibitors,research,lifescience,medical XL184 in vitro ideation. Disabling PSEs occur in less than 1% of patients under mefloquine at therapeutic doses, and in less than 1:10
000 under mefloquine prophylaxis. This indicates that the PSEs are dose-related. However, suicide attempts have even been reported at prophylactic doses.158,159 too Mefloquine PSEs may begin some hours after the first dose.8,160 Their mechanism Is not clearly understood; actions as a N methyl-D-aspartate (NMDA) receptor antagonist or on sigma receptors have been proposed. Chloroquine, another antimalarial, also produces psychiatric and neurological side effects: agitation, aggressiveness, amnesia, confusion, depression, hallucinations, and mania. Psychiatric changes under chloroquine may develop Insidiously. Memory or perception changes can be the only clues to side effects In this developing phase. The half -life of chloroquine Is long at around 1 month. Therefore, remission of a chloroquinerelated PSE may take days.