Bath-related headache induced by varenicline

Abstract

The article by Camara Filho et al. 1 reports the case of a woman with recurrent headache attacks which occurred after the use of varenicline. The usual presentation of bath-related headache is a recurrent sudden severe headache attack (i.e. thunderclap headache) typically triggered by bathing or other activities involving body contact with water 2 . The authors commented the possibility of reversible cerebral vasoconstriction as a cause of bath-related headache 1 . Interestingly, two cases of thunderclap headache have recently been reported 3 associating reversible segmental vasoconstriction with the use of varenicline. The alpha4beta2 nicotinic receptor partial agonist varenicline is a drug authorized for promoting smoking cessation in the USA and Europe. This receptor mediates the primary effects of nicotine on the mesolimbic system, activating the dopaminergic reward pathway. Thus, by acting as a nicotinic antagonist, it inhibits dopamine release, thereby decreasing the effects of smoking satisfaction often associated with nicotine use. It was developed from cytisine, a natural alkaloid compound widely used to increase the chances of a person successfully giving up smoking. Cytisine is found in the Baptisia, Cytisus, Laburnum, and Sophora species, and has nicotine-like effects on the nervous system. These plants may have a recreational purpose when used for smoking because of their stimulant effects and mild hallucinogenic properties. The Sophora root, also known as "Ku Shen", is used in traditional Chinese medicine. The use of such plants by humans, for whatever purpose, may suggest that a particular alimentary/recreational habit might be the reason for a higher prevalence of bath-related headache among Asian populations. Curiously, the usual trigger is hot water, suggesting an imbalance in the thermogenic CNS circuitry. Pharmacological stimulation of α4β2 nicotinic receptors causes changes in body temperature. Indeed, varenicline is able to experimentally modulate hypothermia and antinociception induced by nicotine. This may explain the higher susceptibility (i.e. dysfunctions in craniofacial somatosensory processing) to hot water in contact with the head when someone is undergoing treatment with varenicline. Similar phenomenon occurs in a unique form of reflex epilepsy, i.e. hot water epilepsy 4 . Ravishankar reported 5 that migraine attacks were triggered by hair washing in 94 people in a series of 1,500 Indian migraineurs. Some adverse effects may occur soon after the intake of varenicline, and others developed after several weeks of treatment or even after stopping varenicline. Due to the increasing use of smoking cessation drugs, this fascinating form of headache may be more frequent than generally believed.

Headache Research and Medical Practice in Brazil: An Historical Overview

“…A number of the early articles on headache disorders were published by Farias da Silva and coworkers in the scientific journal Neurobiologia (Recife), which is one of the oldest journals in the area of neurology in Latin America, founded in 1943 by Ulysses Pernambucano. Another important journal containing articles on headache written by Brazilians is Arquivos de Neuropsiquiatria , which was founded in 1945 …”

“…The Federal University of Pernambuco has contributed to the study of headache for almost half a century since the first publication in 1968 . Wilson Farias da Silva, Marcelo Moraes Valença, Pedro Sampaio Rocha Filho, Joaquim Costa Neto, Waldmiro Serva, Fabíola Lys Medeiros, Hugo André Martins, and Daniella Araújo de Oliveira are a few of the researchers that have been involved in the study of different aspects of the diagnosis, physiopathology, and treatment of headache disorders in the Federal University of Pernambuco. Rubem Guedes has also published vast amounts of data on spreading depression, today considered an experimental model to study migraine.…”

The Frequent Unusual Headache Syndromes: A Proposed Classification Based on Lifetime Prevalence

“…Conversely, there are several unusual and curious forms of headache. Bath‐related headache, headache precipitated by an orgasm, and headache associated with laughter are all out‐of‐the‐ordinary varieties of headache, which always arouse public curiosity.…”