Considerations for prescribing pharmacotherapy for the treatment of erectile dysfunction

Papaverine: A Miraculous Alkaloid from Opium and Its Multimedicinal Application

The pharmacological actions of benzylisoquinoline alkaloids are quite substantial, and have recently attracted much attention. One of the principle benzylisoquinoline alkaloids has been found in the unripe seed capsules of Papaver somniferum L. Although it lacks analgesic effects and is unrelated to the compounds in the morphine class, it is a peripheral vasodilator and has a direct effect on vessels. It is reported to inhibit the cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) phosphodiesterase in smooth muscles, and it has been observed to increase intracellular levels of cAMP and cGMP. It induces coronary, cerebral, and pulmonary artery dilatation and helps to lower cerebral vascular resistance and enhance cerebral blood flow. Current pharmacological research has revealed that papaverine demonstrates a variety of biological activities, including activity against erectile dysfunction, postoperative vasospasms, and pulmonary vasoconstriction, as well as antiviral, cardioprotective, anti-inflammatory, anticancer, neuroprotective, and gestational actions. It was recently demonstrated that papaverine has the potential to control SARS-CoV-2 by preventing its cytopathic effect. These experiments were carried out both in vitro and in vivo and require an extensive understanding of the mechanisms of action. With its multiple mechanisms, papaverine can be considered as a natural compound that is used to develop therapeutic drugs. To validate its applications, additional research is required into its precise therapeutic mechanisms as well as its acute and chronic toxicities. Therefore, the goal of this review is to discuss the major studies and reported clinical studies looking into the pharmacological effects of papaverine and the mechanisms of action underneath these effects. Additionally, it is recommended to conduct further research via significant pharmacodynamic and pharmacokinetic studies.

Pharmaceutical management of sexual dysfunction in men on antidepressant therapy

INTRODUCTION

Sexual dysfunction (SD) and depression have a bidirectional relationship. The rising prescription of antidepressants, especially those with a serotonergic effect, is associated with increased SD. Sexual dysfunction reduces compliance and increases risk of recurrence of depressive episodes. Various strategies have been studied to manage antidepressant-induced SD.

AREAS COVERED

This review covers the identification of symptoms of antidepressant-induced SD, prevalence of symptoms in association with commonly used antidepressants, and the main lines of management, with a focus on pharmacological strategies.

EXPERT OPINION

The management of antidepressant-induced SD aims to reduce the unwanted sexual adverse effects while maintaining an acceptable control of depressive symptoms. It should implicate a multidisciplinary approach and determination of baseline sexual function and SD risk factors. In spite of several methodological issues, antidepressants can be divided into low- and high-risk categories with regard to the possibility of developing SD. In patients interested in sexual activity, it is recommended to start with low-risk antidepressants. Otherwise, encourage the patient to wait for tolerance and then switch to low-risk. In selected cases, dose reduction or a drug holiday may be applied. The adjunctive use of a PDE5i can help in a significant number of patients. Randomized controlled trials are needed to set high-level evidence-based recommendations.