Varenicline helps smokers quit smoking
Quitting smoking presents an immense challenge to those affected. The chances of withdrawal success can be increased by nicotine replacement products such as patches or chewing gum. If these attempts fail, a possible alternative is therapy with varenicline. The drug has been tried and tested, and its positive effect on the course of withdrawal has been documented in studies. However, the drug has strong side effects and does not help all smokers.
Effect of varenicline
To prevent smoker’s lung, smoking cessation should be started early. It is best to completely abstain from the toxic smoke. Within a few seconds of ingesting nicotine, the emotion-enhancing effect unfolds in the consumer’s brain. The addictive substance binds to alpha-4-beta-2 receptors in the nerve cells and triggers the formation of acetylcholine (source: spektrum.de). The neurotransmitter immediately excites an area of the brain responsible for the reward. As the stimulatory effect subsides, a desire arises to recreate the experienced state by smoking again. Varenicline intervenes in this mechanism by targeting nicotinic receptors. The binding of the active ingredient still leads to the production of acetylcholine, but to a considerably lesser extent. In contrast to withdrawal without therapy, minimal reward is maintained, attenuating any withdrawal symptoms that do occur. At the same time, varenicline displaces existing nicotine from receptors and prevents the addictive substance from being reconnected. As a result, tobacco use remains effect-free and smoking cravings decrease.
Varenicline as a medication
In Europe, varenicline has been available as a medication under the brand name Champix (Pfizer) since 2006. The drug can be prescribed by physicians to adults for severe nicotine dependence and is taken as a film-coated tablet. Studies for children and adolescents under 18 years of age are not available. The drug is not prescribed during pregnancy because animal studies have shown it to be harmful to offspring. In addition, varenicline passes into breast milk. Therefore, during lactation, either breastfeeding or therapy must be discontinued. Furthermore, researchers from the Pharmacogenomics Research Network recommend determining the patient’s metabolism prior to treatment. A simple blood test is used to determine how quickly nicotine is broken down by the liver. According to the study, varenicline is suitable for individuals with high metabolism (Lancet Respiratory Medicine, vol. 3, no. 2, 131-138, 2015). In contrast, patients who metabolized the addictive drug slowly showed no benefit. In addition, they complained more often of side effects occurring, so in these cases the conventional and less expensive treatment with nicotine replacement products should be preferred. A simple blood test is used to determine how quickly nicotine is broken down by the liver. According to the study, varenicline is suitable for individuals with high metabolism (Lancet Respiratory Medicine, vol. 3, no. 2, 131-138, 2015). In contrast, patients who metabolized the addictive drug slowly showed no benefit. In addition, they complained more often of side effects occurring, so in these cases, conventional and less expensive treatment with nicotine replacement products should be preferred.
Application
Therapy with varenicline should begin before smoking cessation, but can also take place with a parallel reduction in tobacco consumption. During the first seven days, the daily dose is gradually increased to two milligrams, and use is for a total period of at least twelve weeks. The success of the therapy depends to a large extent on the patient’s motivation and can be promoted by targeted behavioral counseling. Here, for example, individual strategies are to be discussed with which the patient can cope with stressful situations and suppress his or her desire to smoke.
Side effects and interactions
The use of varenicline may involve significant side effects. Therefore, the physician must accurately assess the patient’s personal situation before prescribing, weigh the risks and benefits of therapy, and possibly adjust the prescribed dose during treatment. Very often there are disturbances of the digestive system, which manifest themselves as nausea, stomach discomfort, diarrhea and vomiting. Many patients report sleep disturbances and abnormal dreams.In addition, drowsiness and dizziness rarely occur, which leads to restrictions in the general ability to perform and concentrate. Caution is advised here, especially when driving and operating machinery. The list of other, occasionally occurring side effects is long and concerns, among other things, the patient’s appetite and libido, his emotional sensation and the cardiovascular system. In the past, varenicline use has also been associated with an increase in heart attacks, the occurrence of depressive episodes, and practiced suicide. Subsequent studies ruled out a direct connection between the documented cases and the drug as a cause, but patients with a corresponding predisposition are nevertheless advised to critically discuss the implementation of the therapy with their physician in advance. Varenicline continues to interact with other medications. Proven to be affected are:
- Psychotropic drugs (clozapine, olanzapine),
- Painkillers (paracetamol, caffeine),
- The stomachic cimetidine,
- The asthma drug theophylline,
- The blood thinner warfarin, insulin
Conclusion
In smoking cessation, the active ingredient varenicline reduces the craving for nicotine and relieves withdrawal symptoms. The smoker’s motivation to renounce his or her vice remains a basic prerequisite for therapeutic success. Because of numerous side effects and interactions, use must be discussed in detail with the physician.