Finland vs. Sweden: Pharmacogenetics
Genetics. It determines our height and color of our eyes. Did you know that it also affects how we react to certain drugs?
There are variety of enzymes and other proteins in our body that control the drug metabolism, and how they control it, is based on the instructions given by our genome. Variations within these instructive genes create differences in drug metabolism between individuals. Pharmacogenetics studies these features. By using pharmacogenetic testing it is possible to improve the safety and efficacy of medical treatment by finding the correct drug and dosage. This applies to many drugs used in for example pain relief, cardiovascular diseases and psychiatric conditions.
Using drugs with genetic variation in their metabolism is common in Finland and Sweden – so what could be better than a little contest between old friends? What are the differences between these two countries concerning pharmacogenetics and which country has it better? Here is what we found out.
Differences in pain medication
Oxycodone and codein are drugs used commonly in Finland and in Sweden for pain relief: 3 % of Swedes (over 344 000 individuals) were prescribed oxycodone in 2017. Codein was prescribed for 2,6 % (260 000). Oxycodone is not as common in Finland as it is in Sweden: around 0,7 % (39 000) of Finns were prescribed oxycodone. Codein in the other hand, is a little more used in Finland as 3,2 % (174 000) had codein prescriptions.
Oxycodone and codein metabolize into strong opioids through liver enzyme called CYP2D6: oxycodone to oxymorphone and codein to morphine. They are efficient pain relievers when functioning ideally, however due to CYP2D6’s genetically determined activity, the amount of the opioid metabolized can be lower than normal. This leads to inefficient pain relief. If the metabolism of the enzyme is too fast, ultrarapid as it’s called, it can result in serious side effects including nausea and respiratory problems – it can even lead into an addiction. (1) Ultrarapid metabolism is observed in 1-2 % within the caucasian population, although one study estimates that up to 7 % of the Finns are CYP2D6 ultrarapid metabolizers. (2)
Pharmacogenetic testing is an easy way of making sure the planned pain relief is safe and effective.
One study estimates that up to 7 % of the Finns are CYP2D6 ultrarapid metabolizers.
Shared heart and vascular diseases
Challenges in medicating cardiovascular diseases arise from possible renewed stroke or serious side effects. These are all problems that can in some cases be avoided if the genetic features of a patient are considered. Cardiovascular medication is something Finland and Sweden surely do have in common:
Simvastatin is a cholesterol drug which metabolism is greatly affected by variations in the gene called SLCO1B1. In 2017 over 4 % (432 000) of the Swedes and 5,5 % (307 000) of the Finns were prescribed simvastatin. One of the most commonly reported side-effects during simvastatin treatment is muscle pain, which is rarely dangerous itself but can lead to patient discontinuing the treatment. (3) High cholesterol is one of the key factors in generating atherosclerosis, and it can possibly lead to a stroke.
Treatment after a stroke includes medication for preventing platelet clotting and for this clopidogrel is commonly used. 1 % of the population in Sweden (93 000) as well as in Finland (52 000) had a prescription for clopidogrel in 2017. An important factor in the metabolism of clopidogrel is the gene CYP2C19 and knowing the patient’s individual version of this gene is crucial for safety and efficacy of the drug (4). An inoperative drug is likely to have a non-preventive effect for a patient to suffer a renewed stroke.
When testing the pharmacogenetic panel, multiple genes are analyzed with one test: this can be particularly useful for example when clopidogrel medication is considered.
Complex mood medication
Medication used for mood and psyche can be complicated: finding an effective drug and dosage of for example antidepressant may take several months, multiple drugs and variety of unwanted side effects. It takes weeks to find out whether the consumed drug suits a patient, and before an alternative drug is taken into consideration the washout period needs to take place. Finding out patient’s genetic features fastens the process of finding the correct medication.
1,5 % of the Swedes (119 000) and 1,2 % of the Finns (80 890) consumed a SSRI-drug (selective serotonin reuptake inhibitor) escitalopram in 2017. The drug is used to treat diagnosed depression and its metabolism is affected by variations in CYP2C19. Another common depression medicine is venlafaxine: 90 700 patients in Sweden and 54 450 patients in Finland were prescribed this medicine, that metabolizes through CYP2D6.
Pharmacogenetic testing of the properties of CYP2D6 and CYP2C19 supports the process of finding the correct drug and dosage when prescribing certain antidepressants. Experimenting with various medication is not only expensive but can also be painful experience for the patient.
Despite of the small differences in the numbers above, it looks like there really is not much of a competition here. After all, this round shows how similar both teams are with the same health issues and the same medications. Pharmacogenetics could be a way for both of the countries to increase the patient safety and to introduce purely individualized medicine to healthcare.
Presciption statistics from Finnish Social Insurance Institution and Swedish National Board of Health.
1. Crews KR et al. Clinical Pharmacogenetics Implementation Consortium Guidelines for Cytochrome P450 2D6 Genotype and Codein Therapy: 2014 Update. Clin Pharmacol Ther. 2014 Apr;95(4):376-82. doi: 10.1038/clpt.2013.254. Epub 2014 Jan 23.
2. Pietarinen P et al. High Frequency of CYP2D6 Ultrarapid Metabolizer Genotype in the Finnish Population. Basic Clin Pharmacol Toxicol. 2016 Apr 2. doi: 10.1111/bcpt.12590.
3. Ramsey LB et al. The clinical pharmacogenetics implementation consortium guideline for SLCO1B1 and simvastatin-induced myopathy: 2014 update. Clin Pharmacol Ther. 2014 Oct;96(4):423-8. doi: 10.1038/clpt.2014.125. Epub 2014 Jun 11.
4. Scott SA et al. Clinical Pharmacogenetics Implementation Consortium Guidelines for CYP2C19 Genotype and Clopidogrel Therapy: 2013 Update. Clin Pharmacol Ther. 2013 Sep;94(3):317-23. doi: 10.1038/clpt.2013.105. Epub 2013 May 22.
5. Hicks JK et al. Clinical Pharmacogenetics Implementation Consortium (CPIC) Guideline for CYP2D6 and CYP2C19 Genotypes and Dosing of Selective Serotonin Reuptake Inhibitors. Clin Pharmacol Ther. 2015 Aug;98(2):127-34. doi: 10.1002/cpt.147. Epub 2015 Jun 29.