RK.md » drugs

Disulfiram

Rishi — Tue, 08 Jun 2010 06:08:19 +0000

Sometimes, medical therapy is just funny. Disulfiram, one of the drugs we had to learn for pharmacology months ago, is a treatment for chronic alcoholism.

We’re familiar with antibiotics working with the body’s immune system to destroy bacteria and resolve infections. In this case, antibiotics typically interact directly with the bacterial organism (halting protein synthesis, preventing cell wall formation, etc.) and the body has a chance to “catch up” with its immunological onslaught.

Disulfiram works in an interesting way. Since you can’t “target” chronic alcoholism, it’s mechanism is quite simple – if you’re caught drinking alcohol while on disulfiram, you’re going to regret it. Yes, it’s a drug therapy of intimidation.

Alcohol is metabolized by the liver to acetaldehyde (one of the main culprits of the “hangover”) which is subsequently metabolized to harmless acetic acid through acetaldehyde dehydrogenase. Disulfiram acts by inhibiting said enzyme and effectively raising the levels of acetaldehyde in the blood. The result? If you drink even a little alcohol, you’re going to have a miserably prolonged hangover – based on statistics, this has been a sufficient reason for chronic alcoholics to practice abstinence.

Alimta and Lung Cancer

Rishi — Fri, 10 Jul 2009 02:51:23 +0000

Indianapolis-based pharmaceutical giant Eli Lilly & Co. have recently received approval from the FDA for using Alimta (a drug originally approved in 2004 for the treatment of mesothelioma) for maintenance therapy of advanced/metastatic non-smell cell lung cancer (NSCLC).

In a study of 600 patients, those with NSCLC survived an roughly six months longer with Alimta compared to those who received a placebo. A notable exception is the patient group that had the squamous cell subtype of NSCLCL. Unfortunately, Alimta had virtually no benefit on these patients.

Alimta works by disrupting metabolic processes involving folate, a vitamin essential to nucleotide production and consequently cellular reproduction.

Most of Alimta’s side effects can be attributed to damaged blood cells as folate is pivotal in producing healthy RBC’s.

Fighting BRCA Linked Cancer – PARP Inhibition

Rishi — Sat, 27 Jun 2009 01:38:58 +0000

A recent Institute of Cancer Research study published in the New England Journal of Medicine describes a novel way of treating BRCA-gene based cancers. Mutations in the BRCA-1 and BRCA-2 genes are routinely linked with higher incidence of breast and ovarian cancers in women; however, in healthy cells, the aforementioned genes are involved in a repair mechanism.The new drug, Olaparib, works by inhibiting an enzyme (PARP) involved in a different repair mechanism. Since healthy cells have the BRCA-based pathway as well as the PARP pathway, they can always repair themselves using the former method if the latter is inhibited. On the other hand, BRCA-based cancers do not have the BRCA pathway as an option, so inhibiting the PARP pathway destroys their only repair pathway. Quite a mouthful, but simple to understand.

Eliminating two methods of cellular repair sure does pose a threat to the propagation of cancer cells. Studies have shown that healthy cells remain relatively unscathed (since they have several options for self-repair), but cancer cells die. I surmise that future studies will encompass cancers not directly related to a mutation in the BRCA1 and BRCA2 genes.

This is one fork of the future of personalized medicine – using an individual’s own molecular weaknesses for positive results.

I love how fundamental concepts can be used in such radical ways. In this case, analyzing the difference between healthy cells and cancer cells, and exploiting any variations to damage the latter while preserving the former. Medicine really is a grand application of simple ideas.

Lamictal XR Approved

Rishi — Mon, 01 Jun 2009 19:09:02 +0000

Those with stakes in GlaxoSmithKline (NYSE: GSK) were pleased this morning as the stock rose on account of the FDA’s approval of Lamictal XR (“extended release”) . The drug, aimed at epilepsy patients thirteen years of age and older, is intended to reduce seizures in patients who have had unsuccessful results with other therapies.