Genotyping

Medicines are often made active or inactive by enzymes (these are certain proteins) in our liver or intestines. Sometimes such an enzyme works too hard or too slowly. This is determined by our genes.

Suppose: a certain drug does not work for you or it gives serious side effects because too much enters the blood. You may be missing an enzyme or have too much of it.

The pharmacist is a specialist in this field. He will consult with your doctor about the reason for doing an examination. This examination is called a genotyping. The pharmacist will then ask a special laboratory to send you a kit to take a swab from your cheek mucosa. You then send this back and the result is sent to the pharmacy. This will be interpreted by the pharmacist.

This extra service from the pharmacy costs you nothing when your doctor agrees with the research.

Example

You are prescribed tramadol but this painkiller does nothing for you. You should report this immediately because otherwise you are in unnecessary pain. Then you will be given another painkiller and we will start applying for you. Now it is true that tramadol is actually made active by an enzyme. So if you have too little of that enzyme, it will not become active. Now, you may be getting metoprolol for a high heart rate or for heart failure. This very drug is made inactive by the same enzyme. This means that you actually need a much lower dose of metoprolol to get the same effect because far too little metoprolol is made inactive.

Did you know that this can be life-threatening? Because suppose you end up in the hospital with a very high heart rate. And you are unable to tell that you are missing that enzyme. Then the specialist may give you metoprolol, usually by injection or infusion, to bring the heart rate down. The metoprolol is then dosed way too high which can lead to a life-threatening slow heart rate or even cardiac arrest. This is prevented by genoytpering.