Posted by ed_uk2010 on August 6, 2010, at 17:09:52
In reply to Guess work, blood work, death work » ed_uk2010, posted by Brainbeard on August 6, 2010, at 15:33:59
>It does involve guesswork. Subjective measurements are suspect by nature....
Depression is all about subjective experiences though. Only the patient can say whether or not they are finding any given dose to be effective.
>Clomipramine has non-linear pharmacokinetics: on higher doses, blood levels increase exponentially in relation to dose, supposedly because of its self-inhibiting metabolism.
Especially at 150mg/day plus. I do think it makes sense to perform blood levels for patients on very high doses. If someone was experiencing relief on 30mg/day and they weren't suffering from any side effects, I do not think that it would generally be necessary to measure the blood level.
>People have died from toxic doses without experiencing severe side-effects in advance.
There is a risk of cardiac arrhythmias with most TCAs. Sinus tachycardia is extremely common and generally benign; more serious arrhythmias such as torsades de points occur rarely. This risk of serious arrhythmias is highly dependent on the patient eg. increased likelihood in ischemic heart disease, serum electrolyte disturbances, chronic heart failure etc. Such factors should be taken into account when deciding whether bloodwork and other tests are needed before (and during) treatment with TCAs. Performing the same tests on everyone is not appropriate. Interestingly, clomipramine appears to be considerably less toxic in overdose than amitriptyline. Its cardiotoxicity is less but there is a risk of seizures. Patients on very high doses should carefully consider whether or not it is appropriate for them to drive.
poster:ed_uk2010
thread:956845
URL: http://www.dr-bob.org/babble/20100731/msgs/957550.html