Safety and Effectiveness Study of Maca Root to Treat Antidepressant-Induced Sexual Dysfunction

A Dose-Finding Study of the Tolerability and Efficacy of Maca Root in Patients With Antidepressant-Induced Sexual Dysfunction

The purpose of this study is to determine the dose of Maca Root effective for the treatment of antidepressant-induced sexual dysfunction in patients with DSM-IV defined Major Depressive Disorder. We propose to carry out a dose-finding pilot study to determine the minimum effective dose of Maca Root. We hypothesize that patients who receive Maca Root will experience alleviation of their sexual dysfunction, and this effect will be more pronounced in those who receive higher doses of maca root.

The purpose of this study is to determine whether Maca Root is effective for the treatment of antidepressant-induced sexual dysfunction, and to further determine whether higher doses of Maca Root powder would be more effective than lower doses in reducing the symptoms of antidepressant-induced sexual dysfunction. An additional aim of the study is to document the safety and tolerability of Maca Root, which could be particularly helpful in treating antidepressant-induced sexual dysfunction in elderly and cardiac-impaired populations taking oral nitrates who may not be eligible for treatment with the current oral phosphodiesterase inhibitors.

Subjects will be randomized into two arms of 10 for this 12-week study. The study will be double blind with regard to doses received. Ten subjects will receive 1500mg/day of maca for the 12-week period and the other 10 subjects will receive 3000mg/day of maca per day for the 12-week study period. Patients will be seen every other week. There is no placebo arm.

At the final study visit, week 12, subjects will be evaluated to see if their sexual function has returned.

After careful review of the literature we have found that there are very few studies that have evaluated Maca Root in humans. However the one very relevant study completed by Gonzalez and colleagues looked at doses of 1500 and 3000mg in men and found there were increased sexual interests on both doses. Thus, since this is a dose-finding study we believe this dose is an appropriate place to begin.

Hypotheses A:

The response rate will be higher for the high-dose maca group compared to the low-dose group; and this response will be comparable to the 50-85% reported with sildenafil.

Hypothesis B:

There will be a statistically significant difference in the magnitude of response between the two testing conditions, as measured by a decrease in baseline sexual dysfunction scores. The reduction in sexual dysfunction scores will be greater in the high-dose maca group than in the low-dose maca group.

Inclusion Criteria:

• Subjects have been taking an SSRI, venlafaxine, nefazodone, or tri/hetero cyclic antidepressant for treatment of depression for at least 8 weeks, are currently at a stable dose of the antidepressant for at least 4 weeks, and have been consistently experiencing arousal dysfunction (inability to attain or maintain an adequate lubrication/swelling response of sexual excitement until completion of sexual activity) or orgasmic dysfunction (delayed orgasm/anorgasmia following a normal sexual excitement phase) that interferes with sexual function for at least 4 weeks.

Subjects must currently be euthymic (HAM-D< 10) and without significant anxiety symptoms (HAM-A<10). These scales will rely on retrospective reporting from the participant.

Subjects must have had no sexual dysfunction prior to taking an antidepressant and there must be a clear temporal relationship between the sexual dysfunction and the antidepressant treatment. Sexual dysfunction occurring as a symptom of the depressive disorder for which the antidepressant treatment was initiated is not considered to be a pre-existing condition under this definition.

• Subjects must meet at least one of the following criteria:

  • Inability to have an orgasm (anorgasmia), according to patient opinion
  • Clinically significant orgasm delay with masturbation or intercourse that according to patient opinion represents a meaningful delay and interferes with subject's sexual function compared with the subject's usual time to achieve orgasm in response to sexual stimulation prior to antidepressant medication
  • Inability to attain or maintain until completion of sexual activity an adequate an erection or lubrication swelling response of sexual excitement that, according to patient opinion, interferes with subject's sexual function, compared to prior to antidepressant medication.
  • Decreased libido according to patient opinion (and verified by objective measurements)

• Subjects must experience at least one of the above criterion items with distress and or disability.

• Subjects must be having or had been having some form of regular sexual activity (masturbation, oral sex, intercourse) at least twice monthly prior to the antidepressant treatment and are willing to continue efforts at sexual activity at least once weekly for the duration of the study

• Subjects must be in good general physical health

Exclusion Criteria:

• Primary or prior diagnosis of a sexual disorder (other than the side effect of the antidepressant drug or symptom of major depression)
• Sexual dysfunction secondary to general underlying medical condition
• Any uncontrolled psychiatric disorder
• Alcohol or substance abuse or dependence within the past six months
• Recent major relationship changes, disruption, or turmoil ongoing or anticipated which are unrelated to their sexual dysfunction
• Hamilton Depression and/or Anxiety Scale score (either) >10
• Blood pressure outside the range of 90/50 - 170/100
• Use of investigational drugs within prior 3 months or during study.
• Current use of other drugs for antidepressant induced sexual dysfunction or other therapies or medications to treat sexual dysfunction
• Hormone replacement therapy, unless patient has been on stable dose of hormone therapy for at least 3 months prior to the antidepressant treatment and had no sexual dysfunction while on the same hormone therapy regimen, and there is no change in the hormone replacement therapy during the study
• Pregnancy, lactating, or planning to become pregnant during the study
• Child bearing potential subjects unwilling and/or not prepared and/or who are judged unreliable to use an acceptable and verifiable form of contraception during the study
• Any clinically significant abnormality of the screening physical examination
• History of elevated PSA levels that are greater than 0.2 (as defined by MGH labs)
• History of prostate or other hormonal cancers
• Prior use of maca for at least two weeks
• Infection of the urogenital tract that may make sexual activity painful or difficult
• Subjects whose sexual partners are suffering from and/or receiving treatment for sexual dysfunction
• Receiving psychosexual or other therapy for sexual dysfunction and not willing to discontinue that treatment at screening
• Subjects not attempting some form of regular sexual activity at least twice monthly and at least once weekly during study visit intervals for the duration of the entire study
• Changes in antidepressant agent and/or dose of prescribed antidepressant agent.