Treatments for long-lasting and painful erection of the penis in boys and men with sickle cell disease

Review question

What are the benefits and risks of different treatments for stuttering (repeated short episodes) and fulminant (lasting for six hours or more) priapism in sickle cell disease?

Background

Priapism (the prolonged painful erection of the penis) is common in males with sickle cell disease. The length of time priapism lasts differs for different types and so does the medical treatment for it. Self-management approaches may be helpful. We looked for randomised controlled trials of different treatments to find the best option.

Search date

We last looked for evidence on 09 September 2019.

Study characteristics

We found three trials set in Jamaica, Nigeria and the UK involving 102 people.

Key results

In the trials, four different drug treatments (stilboestrol, sildenafil, ephedrine and etilefrine) were compared to placebo. The trials all looked at whether the treatments reduced how often attacks of priapism occurred. There was no difference between any of the treatments compared to placebo. Due to lack of high-quality evidence, we are not able to conclude the best treatment of priapism in sickle cell disease. More research is needed. This is an update of a previously published review.

Quality of the evidence

We considered the quality of evidence to be low to very low as all of the trials were at risk of bias and all had low participant numbers.

Authors' conclusions: 

There is a lack of evidence for the benefits or risks of the different treatments for both stuttering and fulminant priapism in sickle cell disease. This systematic review has clearly identified the need for well-designed, adequately-powered, multicentre randomised controlled trials assessing the effectiveness of specific interventions for priapism in sickle cell disease.

Read the full abstract...
Background: 

Sickle cell disease comprises a group of genetic haemoglobin disorders. The predominant symptom associated with sickle cell disease is pain resulting from the occlusion of small blood vessels by abnormally 'sickle-shaped' red blood cells. There are other complications, including chronic organ damage and prolonged painful erection of the penis, known as priapism. Severity of sickle cell disease is variable, and treatment is usually symptomatic. Priapism affects up to half of all men with sickle cell disease, however, there is no consistency in treatment. We therefore need to know the best way of treating this complication in order to offer an effective interventional approach to all affected individuals. This is an update of a previously published review.

Objectives: 

To assess the benefits and risks of different treatments for stuttering (repeated short episodes) and fulminant (lasting for six hours or more) priapism in sickle cell disease.

Search strategy: 

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register, which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also searched trial registries.

Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 09 September 2019.

Date of most recent search of trial registries and of Embase: 01 October 2019.

Selection criteria: 

All randomised or quasi-randomised controlled trials comparing non-surgical or surgical treatment with placebo or no treatment, or with another intervention for stuttering or fulminant priapism.

Data collection and analysis: 

The authors independently extracted data and assessed the risk of bias of the trials.

Main results: 

Three trials with 102 participants were identified and met the criteria for inclusion in this review. These trials compared stilboestrol to placebo, sildenafil to placebo and a four-arm trial which compared ephedrine or etilefrine to placebo and ranged in duration from two weeks to six months. All of the trials were conducted in an outpatient setting in Jamaica, Nigeria and the UK. None of the trials measured our first primary outcome, detumescence. However, all three trials reported on the reduction in frequency of stuttering priapism, our second primary outcome; and from the evidence included in this review, we are uncertain whether stilboestrol, etilefrine or ephedrine reduce the frequency of stuttering priapism as the certainty of the evidence has been assessed as very low. Additionally, we conclude that sildenafil may make little or no difference (low-certainty evidence). Two trials reported on immediate side effects and we are uncertain whether etilefrine or ephedrine reduce the occurrence of these (very low-certainty of evidence) and also conclude that sildenafil may make little or no difference in side effects (low-quality evidence). Given that all of the trials were at risk of bias and all had low participant numbers, we considered the certainty of the evidence to be low to very low.