Pregabalin dependence - A rising concern

Dear Editor, The pregabalin dependence is an emerging entity which requires attention and further research. The use of tricyclic antidepressants in the management of pregabalin dependence has not been studied so far. We believe that amitriptyline can be used safely in pregabalin dependence, as it has shown astonishing results in the index case, although it may vary from patient to patient. Pregabalin is a newer generation antiepileptic that exerts its effect by decreasing the release of neurotransmitters such as glutamate, substance P, and noradrenaline. The mechanism of action of pregabalin is not clearly understood, but it has been explained that it affects excitatory neuronal transmission via a2-d ligands in voltage-gated calcium channels1 and decreases the release of such neurotransmitters as glutamate, noradrenaline, and substance P.2 Besides its use in partial epilepsy, it is also used in the treatment of neuropathic pain, fibromyalgia, and generalized anxiety disorder. Studies have shown its usefulness in the treatment of benzodiazepine dependence and withdrawal, as well as preventing relapse in patients with alcohol dependence.3 As pregabalin is being used in a wide variety of indications, its abuse potential is increasing alarmingly. Studies have shown that pregabalin can cause psychiatric symptoms during withdrawal such as insomnia, anxiety, sadness of mood, loss of interest in earlier pleasurable activities, and decreased appetite for skipping pregabalin.3-5 Here, we describe a case of pregabalin dependence. A 35-year-old male was referred to the psychiatry outpatient department for vague somatic complaints after receiving normal blood investigations. He has a history of tobacco dependence that started in early adulthood and is currently smoking 10-12 cigarettes per day. The patient started using pregabalin 4 years back at the dose of 75 mg at night following the recommendation of a physician for somatic complaints and reported feeling relaxed, euphoric effects, energetic, and would have good sleep after taking pregabalin. He continued it without a prescription and increased the dose to 1000 mg to get the same desired effects. If he does not take it, his withdrawal symptoms included anxiety, irritability, aggression, decreased sleep, decreased appetite, headache, feeling of tightening and needle-piercing sensations in hands and feet, and decreased energy to do work. The patient tried to leave pregabalin on his own for financial reasons and had difficulty getting it without a prescription. However, he could not do so because of the abovementioned withdrawal symptoms. His family relations and professional performance also suffered due to his pregabalin use. There was no significant past and family history. After evaluation in our psychiatry department, the patient has prescribed amitriptyline 25 mg, which was gradually increased to 100 mg, with gradual tapering off the pregabalin by 50 mg per week for 12 weeks, followed by 100 mg per week for the next 4 weeks. The patient has been off pregabalin for the last 4 weeks and taking amitriptyline 100 mg at night. The patient responded well to the treatment and reports occasional sleep disturbances.6-9 The present case explains the tenuous evidence from earlier studies on physical dependence in people using pregabalin. Although pregabalin has a low propensity to cause dependence, it still poses a risk because of its euphoric effect.8,10,11 Clinicians need to be aware that regular doses of pregabalin have the potential to cause physical dependence. It is also important to take note of the duration of pregabalin use.1 Since there is a scarcity of studies about pregabalin dependence, not much is known about its treatment. Recent data suggest that comparable caution should be used while giving pregabalin. Individuals may fabricate or exaggerate their symptoms to be able to get fresh prescriptions or force a titration to higher doses.11 Thus, it becomes extremely important for prescribers to be aware of populations at higher risk of pregabalin abuse, including patients with psychiatric or substance use disorder, and monitor for signs of abuse or diversion. As pregabalin plays an important role in various chronic conditions and several psychiatric problems in addition to epilepsy, so its use cannot be restricted as per recent research evidence, but rather that a bigger focus be put on identifying indications and risk factors of abuse as well as safe prescribing in people who are addicted to alcohol or other drugs. In conclusion, there is a need for further research on abuse and addiction potential and pregabalin abuse and its treatment in the future. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.