Single dose sublingual testosterone and oral sildenafil vs. a dual route/dual release fixed dose combination tablet: a pharmacokinetic comparison

The Role of Bupropion in the Treatment of Women with Sexual Desire Disorder: A Systematic Review and Meta-Analysis

Although few clinical trials examined the efficacy of bupropion to treat sexual dysfunction among female patients, a comprehensive and objective synthesis of the best available evidence is still lacking. To date, to the best of our knowledge, there are no published systematic reviews or meta-analyses specifically focusing on the role of bupropion in the treatment of female sexual dysfunction. The main objective of the present study was to evaluate the efficacy of bupropion in the treatment of female sexual dysfunction, and we hypothesized that bupropion is efficient in treating female patients with sexual dysfunction. This review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search for published literature was performed using Ovid, Medline, Scopus, Cochrane Library, Science Direct, and PubMed databases. In our study, we found that bupropion was almost three-fold more favorable in improving problems with sexual desire (pool estimate 2.845, 95% CI: 0.215 to 5.475, I2= 95.6%, p=0.034). A meta-regression was performed to explore heterogeneity and we found that only the dosage of bupropion was statistically significant in explaining the variance, i.e., the lower the dosage (150 mg vs. 300 mg), the better the improvement in the sexual desire of women with hypoactive sexual desire disorder (HSDD). Based on the results of this systematic review and metaanalysis, there is a potential role of bupropion as an effective treatment for women with HSDD.

A survival of the fittest strategy for the selection of genotypes by which drug responders and non-responders can be predicted in small groups

Phenotype Prediction Scores (PPS) might be powerful tools to predict traits or the efficacy of treatments based on combinations of Single-Nucleotide Polymorphism (SNPs) in large samples. We developed a novel method to produce PPS models for small samples sizes. The set of SNPs is first filtered on those known to be relevant in biological pathways involved in a clinical condition, and then further filtered repeatedly in a survival strategy to select stabile positive/negative risk alleles. This method is applied on Female Sexual Interest/Arousal Disorder (FSIAD), for which two subtypes has been proposed: 1) a relatively insensitive excitatory system in the brain for sexual cues, and 2) a dysfunctional activation of brain mechanisms for sexual inhibition. A double-blind, randomized, placebo-controlled cross-over experiment was conducted on 129 women with FSIAD. The women received three different on-demand drug-combination treatments during 3 two-week periods: testosterone (0.5 mg) + sildenafil (50 mg), testosterone (0.5 mg) + buspirone (10 mg), or matching placebos. The resulted PPS were independently validated on patient-level and group-level. The AUC scores for T+S of the derivation set was 0.867 (95% CI = 0.796-0.939; p<0.001) and was 0.890 (95% CI = 0.778-1.000; p<0.001) on the validation set. For T+B the AUC of the derivation set was 0.957 (95% CI = 0.921-0.992; p<0.001) and 0.869 (95% CI = 0.746-0.992; p<0.001) for the validation set. Both formulas could reliably predict for each drug who benefit from the on-demand drugs and could therefore be useful in clinical practice.

Medicinal Use of Testosterone and Related Steroids Revisited

Testosterone derivatives and related compounds (such as anabolic-androgenic steroids—AAS) are frequently misused by athletes (both professional and amateur) wishing to promote muscle development and strength or to cover AAS misuse. Even though these agents are vastly regarded as abusive material, they have important pharmacological activities that cannot be easily replaced by other drugs and have therapeutic potential in a range of conditions (e.g., wasting syndromes, severe burns, muscle and bone injuries, anemia, hereditary angioedema). Testosterone and related steroids have been in some countries treated as controlled substances, which may affect the availability of these agents for patients who need them for therapeutic reasons in a given country. Although these agents are currently regarded as rather older generation drugs and their use may lead to serious side-effects, they still have medicinal value as androgenic, anabolic, and even anti-androgenic agents. This review summarizes and revisits the medicinal use of compounds based on the structure and biological activity of testosterone, with examples of specific compounds. Additionally, some of the newer androgenic-anabolic compounds are discussed such as selective androgen receptor modulators, the efficacy/adverse-effect profiles of which have not been sufficiently established and which may pose a greater risk than conventional androgenic-anabolic agents.

The Effect of Food on the Pharmacokinetics of Buspirone After Single Administration of a Sublingual Testosterone and Oral Buspirone Combination Tablet in Healthy Female Subjects

Introduction

A new combination tablet containing sublingual testosterone and oral buspirone (T+B) was developed to benefit a subgroup of women suffering from female sexual interest/arousal disorder, caused by dysfunctionally overactive sexual inhibition.

Aim

The aim of this study was to compare the effect of food intake on the pharmacokinetics of buspirone, administered as a dual-route, dual-release combination tablet containing 0.5 mg testosterone (T) and 10 mg buspirone (B).

Methods

19 healthy women took T+B under fed and fasted conditions during 2 overnight visits. The blood was sampled over a 24-hour period to determine the pharmacokinetics of buspirone and its active metabolite 1-(2-pyrimidinyl)piperazine (1-PP). Total testosterone levels were also assessed, at 5 time points and for quality control purposes only, as sublingual testosterone uptake is not expected to be influenced by prior food intake.

Main Outcome Measure

PK profiles of buspirone and 1-PP.

Results

For buspirone, the 90% confidence intervals (CIs) of the observed fed/fasted ratios for the plasma area under the curve (AUC)_0-last, AUC_0-inf, and C_max after administration of T+B were not contained within the prespecified bounds of 80% and 125%, except for the lower bound of AUC_0-inf. However, the 90% CIs of the observed fed/fasted ratios for the plasma AUC_0-last, AUC_0-inf, and C_max of 1-PP were contained within the prespecified bounds, with the exception of the upper bound for C_max. The mean AUCs and C_max for 1-PP did not differ between fed and fasted conditions.

Conclusions

Administration of T+B after high-caloric food intake increased the bioavailability of buspirone but did not result in differences in T_max when compared with fasted conditions. Both in fed and fasted conditions, T+B was generally well tolerated and safe. Exposure of 1-PP in fed and fasted conditions was comparable in both conditions. These results demonstrate that T+B can safely and effectively be used in both fed and fasted states.

Gerritsen J, Bloemers J, van Rooij K, et al. The Effect of Food on the Pharmacokinetics of Buspirone After Single Administration of a Sublingual Testosterone and Oral Buspirone Combination Tablet in Healthy Female Subjects. J Sex Med 2020;8:186–194.

Testosterone therapy and other treatment modalities for female sexual dysfunction

PURPOSE OF REVIEW

Recently in October 2019 a Global Consensus Position on the use of Testosterone Therapy for Women was published. The use of testosterone and other agents for female sexual dysfunction (FSD) is an important topic for the urologist focusing on sexual health. This review describes the known causes for FSD, and discusses the role of androgens in this disorder, the evidence for using testosterone treatment, and other current and emerging therapies.

RECENT FINDINGS

A recent meta-analysis, published in The Lancet Diabetes & Endocrinology evaluated a total of 36 randomized control trials spanning 1990-2018 and includes a total of 8480 patients. The primary findings were that testosterone therapy (TTh) increased sexual function including satisfactory sexual event frequency, sexual desire, pleasure, arousal, orgasm, responsiveness, and self-image when compared with either a placebo or drug-control (e.g., estrogen ± progestogen). In addition, TTh reduced sexual concerns and distress in postmenopausal women. Side effects included an increase in weight, acne, and hair growth, but there was no increase in serious adverse events. Importantly, TTh duration was greater than 12 weeks in all randomized control trials included in this meta-analysis.

SUMMARY

TTh is effective to treat FSD in postmenopausal women. More data is required to evaluate the long-term safety data on the effects of TTh on cardiovascular health, breast health, cognitive function, and the musculoskeletal system in women.

The Effect of Food on the Pharmacokinetics of Sildenafil after Single Administration of a Sublingual Testosterone and Oral Sildenafil Combination Tablet in Healthy Female Subjects

INTRODUCTION

Female sexual interest/arousal disorder (FSIAD) affects many women worldwide, but pharmacological treatment options are scarce. A new medicine being developed for FSIAD is an on-demand, dual-route, dual-release drug combination product containing 0.5 mg testosterone (T) and 50 mg sildenafil (S), referred to here as T+S.

AIM

The aim of this study was to compare the effect of a fed and a fasted state on the pharmacokinetics of sildenafil following administration of T+S.

METHODS

Eighteen healthy women were administered T+S under fed and fasted conditions during 2 separate overnight visits in this randomized, open-label, balanced, 2-period, 2-treatment, 2-sequence crossover study.

MAIN OUTCOME MEASURES

The pharmacokinetics of sildenafil and its active metabolite N-desmethyl sildenafil were determined over a 24-hour period. Total testosterone was assessed only at a limited number of time points for quality purposes, as sublingual uptake is not expected to be affected by food intake.

RESULTS

The observed geometric mean ratios (GMRs) and 90% confidence intervals of sildenafil were not all contained within the prespecified bounds (0.80, 1.25). The GMR (90% CI) for plasma AUC_0-last was 1.2753 (0.9706-1.6755); for AUC_0-14h, it was 1.7521 (1.0819-2.8374); and for C_max, it was 1.5591 (0.8634-2.8153). Only lower limits of the CIs fell within the bounds. For N-desmethyl sildenafil, the GMR (90% CI) for AUC_0-last was 0.8437 (0.6738-1.0564); for AUC_0-10h, it was 1.0847 (0.7648-1.5383); and for C_max, it was 1.0083 (0.6638-1.5318). Only the GMRs were contained within bounds. No differences were observed between plasma testosterone C_max and T_max under fed and fasted conditions, which is in line with expectations for a sublingual administration.

CLINICAL IMPLICATIONS

The T+S combination tablet ruptures too late when taken in a fasted state and should therefore not be taken on an empty stomach.

STRENGTHS & LIMITATIONS

This is a well-controlled study that provides important insights into the performance characteristics of the delayed-release coating of the combination tablet. The higher variability of the pharmacokinetic parameters in the fasted state was caused by severely delayed rupture in one-third of the women. A reason for this is proposed but the present data do not explain this phenomenon.

CONCLUSION

The pharmacokinetics of sildenafil from this modified-release tablet are more robust under fed conditions as compared to the artificial fasted condition where no food is consumed 10 hours prior to and 4 hours after dosing. The dosing situation under the tested fasting condition does not represent the expected common use of this product. Patients should, however, be instructed not to take the tablet on an empty stomach. Bloemers J, Gerritsen J, van Rooij K, et al. The Effect of Food on the Pharmacokinetics of Sildenafil After Single Administration of a Sublingual Testosterone and Oral Sildenafil Combination Tablet in Healthy Female Subjects. J Sex Med 2019; 19:1433-1443.

Genotype scores predict drug efficacy in subtypes of female sexual interest/arousal disorder: A double-blind, randomized, placebo-controlled cross-over trial

Attempts to develop a drug treatment for female sexual interest/arousal disorder have so far been guided by the principle of ‘one size fits all’, and have failed to acknowledge the complexity of female sexuality. Guided by personalized medicine, we designed two on-demand drugs targeting two distinct hypothesized causal mechanisms for this sexual disorder. The objective of this study was to design and test a novel procedure, based on genotyping, that predicts which of the two on-demand drugs will yield a positive treatment response. In a double-blind, randomized, placebo-controlled cross-over experiment, 139 women with female sexual interest/arousal disorder received three different on-demand drug-combination treatments during three 2-week periods: testosterone 0.5 mg + sildenafil 50 mg, testosterone 0.5 mg + buspirone 10 mg, and matching placebo. The primary endpoint was change in satisfactory sexual events. Subjects’ genetic profile was assessed using a microarray chip that measures 300,000 single-nucleotide polymorphisms. A preselection of single-nucleotide polymorphisms associated with genes that are shown to be involved in sexual behaviour were combined into a Phenotype Prediction Score. The Phenotype Prediction Score demarcation formula was developed and subsequently validated on separate data sets. Prediction of drug-responders with the Phenotype Prediction Score demarcation formula gave large effect sizes (d = 0.66 through 1.06) in the true drug-responders, and medium effect sizes (d = 0.51 and d = 0.47) in all patients (including identified double, and non-responders). Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the Phenotype Prediction Score demarcation formula were all between 0.78 and 0.79, and thus sufficient. The resulting Phenotype Prediction Score was validated and shown to effectively and reliably predict which women would benefit from which on-demand drug, and could therefore also be useful in clinical practice, as a companion diagnostic establishing the way to a true personalized medicine approach.

Single dose sublingual testosterone and oral sildenafil vs. a dual route/dual release fixed dose combination tablet: a pharmacokinetic comparison

AIM

The aim was to compare the pharmacokinetic profiles of two formulations of a combination drug product containing 0.5 mg testosterone and 50 mg sildenafil for female sexual interest/arousal disorder. The prototype (formulation 1) consists of a testosterone solution for sublingual administration and a sildenafil tablet that is administered 2.5 h later. The dual route/dual release fixed dose combination tablet (formulation 2) employs a sublingual and an oral route for systemic uptake. This tablet has an inner core of sildenafil with a polymeric time delay coating and an outer polymeric coating containing testosterone. It was designed to increase dosing practicality and decrease potential temporal non-adherence through circumventing the relatively complex temporal dosing scheme.

METHODS

Twelve healthy premenopausal subjects received both formulations randomly on separate days. Blood was sampled frequently to determine the pharmacokinetics of free testosterone, total testosterone, dihydrotestosterone, sildenafil and N-desmethyl-sildenafil.

RESULTS

Formulation 2 had a higher maximum concentration (Cmax ) for testosterone, 8.06 ng ml(-1) (95% confidence interval [CI] 6.84, 9.28) and higher area under the plasma concentration-time curve (AUC), 7.69 ng ml(-1)  h (95% CI 6.22, 9.16) than formulation 1, 5.66 ng ml(-1) (95% CI 4.63, 6.69) and 5.12 ng ml(-1)  h (95% CI 4.51, 5.73), respectively. Formulation 2 had a lower Cmax for sildenafil, 173 ng ml(-1) (95% CI 126, 220) and a lower AUC, 476 ng ml(-1)  h (95% CI 401, 551) than formulation 1, 268 ng ml(-1) (95% CI 188, 348) and 577 ng ml(-1)  h (95% CI 462, 692), respectively. Formulation 2 released sildenafil after 2.75 h (95% CI 2.40, 3.10).

CONCLUSIONS

The dual route/dual release fixed dose combination tablet fulfilled its design criteria and is considered suitable for further clinical testing.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Female sexual interest/arousal disorder (FSIAD) is a significant problem impacting psychological well-being, but the pharmacotherapeutic options for this problem are lacking. The combined, on-demand, sublingual administration of low dose sublingual testosterone and oral administration of sildenafil is a novel pharmacotherapeutic option under development for FSIAD. In proof-of-concept trials, these compounds were successfully administered via different dosage forms (sublingual and oral) at different time points (separated by 2.5 h) because of their markedly different pharmacokinetic-pharmacodynamic profiles. For future larger scale studies and the clinical practice, this raises obvious adherence issues.

WHAT THIS STUDY ADDS

A newly developed dual route/dual release fixed dose combination tablet containing testosterone and sildenafil mimics the pharmacokinetic profile of these components when they are administered as different dosage forms, 2.5 h apart. This combination tablet is a suitable final pharmaceutical drug product that will be used in future studies.