A comparative Study of Tadalafil versus Tadalafil combined with Alpha Lipoic Acid in the treatment of Erectile Dysfunction in Diabetic Patients

INTRODUCTION

Erectile dysfunction (ED) is characterized by a persistent failure to achieve or sustain a sexually satisfying erection.¹It is an age-related disease, with roughly 5% of males between the ages of 20–39 years, 14.8% of males between 40–59 years, and 70% of males aged 70 years and older suffering from it. ² The etiologies of ED include neurogenic, vasculogenic, endocrine, psychogenic, and drug induced.³

Tadalafil is one of Oral phosphodiesterase type 5 inhibitors (PDE5i) (sildenafil, tadalafil, vardenafil and avanafil). The first-line treatment for ED is PDE5i.  PDE5i does not cause spontaneous erections; however, erections do occur when combined with sexual arousal (visual, cerebral, or physical). PDE5i is responsible for the hydrolysis of cyclic guanylate monophosphate (cGMP) to 5′GMP, which causes penile cavernous smooth muscle relaxation and penile erection.⁴

Diabetic erectile dysfunction (DED) is a form of ED that is a subtype of endocrine erectile dysfunction (EED). It's one of the most frequent reasons for dysfunction in diabetics, with a complicated pathophysiology.⁵

DED appears at a young age and is three times more common in diabetic males than in nondiabetic males, affecting about 35–90% of men with diabetes.⁶

ALA is among the most effective biological antioxidants, and because of its water and fat solubility, it is referred to as a "universal antioxidant".⁷

ALA is a significant antioxidant that helps to prevent diabetes and its sequelae. It is commonly referred to as a universal antioxidant as it has the ability to regenerate additional antioxidants such as vitamin C, vitamin E, coenzyme Q10, and glutathione.⁸

Extensive data shows that ALA may be useful in decreasing glucose levels in diabetes patients by affecting the intracellular redox state, which influences insulin action and insulin resistance.⁹

This work aimed to compare the efficacy of ALA (Thioctic acid 300 mg) daily when it combined with tadalafil 5mg daily versus Tadalafil 5mg daily alone in patients with T2D with erectile dysfunction.

PATIENTS AND METHODS

From March 2020 to October 2021, this study was conducted on 40 diabetic patients with ED. The patients were detected by history (medical, sexual, International Index of Erectile Function (IIEF-5) Questionnaire, examination (general, genital), intracavernosal injection (ICI), and investigations such as fasting plasma glucose (FBS), HBA1C, total cholesterol, triglycerides, serum prolactin, and serum total testosterone for all patients.

The patients were able to read and give agreements. Patients under 18 years old, on medications that interfere with the drugs in the study and with sever end organ damage, were excluded. Patients have been chosen from the Dermatology, Venereology, and Andrology Department of the Faculty of Medicine Al-Azhar University Hospitals' outpatient clinic.

The studied patient group:

All the studied patients started the therapy with tadalafil 5 mg every day for 6 weeks. ALA (Thioctic acid, 300 mg) was added to the previous regimen for an additional 6 weeks.

The patients were evaluated according to IIEF-5 questionnaire and were obtained before starting treatment and after 6 weeks from adding tadalafil 5 mg daily then 6 weeks after adding ALA (Thioctic acid 300 mg) daily to tadalafil.

An approved was obtained from the Ethical Research Board (ERB) of the Faculty of Medicine, Al-Azhar University, Cairo, Egypt. Before the study proceeding, all patients assigned informed consent after the obvious explanation of the possible adverse events.

RESULTS

The current research involved 40 diabetic patients who had ED. The Statistical Program for Social Science (SPSS) version 24 was used to investigate the data. The mean±average deviation (SD) has been employed to express quantitative statistics. Frequencies and percentages have been employed to express qualitative statistics. All patients studied had a mean age of 47.9 ± 9.7 years with minimum age of 28 years and maximum age of 66 years (Table 1 & 2).

The mean duration of ED of all studied patients was 3.44 ± 2.6 years with minimum duration of 0.25 years and maximum duration of 11 years (Table 2).

All patients in the study were evaluated for medical diseases and revealed that 100 % of patients (n=40) had DM, 37.5 % of patients (n=15) had hypertension, 30 % of patients (n=12) had benign prostatic hyperplasia (Table 3).

Table 1: Description of age in all studied patients.

Table 2: Description of duration in all studied patients.

Table 3: Description of medical diseases in all studied patients.

The current study showed a statistically significant (p-value < 0.05) increased IIEF after tadalafil (19.1 ± 2.9) when compared with IIEF before treatment (17.3 ± 2.5). There was highly statistically significant (p-value < 0.001) increased IIEF after combination (20.5 ± 3.4) when compared with IIEF before treatment (17.3 ± 2.5). There was statistically significant (p-value < 0.05) increased IIEF after combination (20.5 ± 3.4) when compared with IIEF after tadalafil (19.1 ± 2.9) (Table 4).

Table 4: Comparison of IIEF before treatment and after tadalafil in studied patients. (T: independent sample T test; S: p-value < 0.05 is regarded as significant.).

Table 5: Comparison of IIEF before treatment and after Combination in studied patients. This table displays statistically significant (p-value < 0.05) increased IIEF after tadalafil (19.1 ± 2.9) when compared with IIEF before treatment (17.3 ± 2.5). (MW: Mann Whitney U test; HS: p-value < 0.001 is regarded as highly significant).

Table 6: Comparison of IIEF after tadalafil and after Combination in studied patients. This table displays highly statistically significant (p-value < 0.001) increased IIEF after combination (20.5 ± 3.4) when compared with IIEF before treatment (17.3 ± 2.5). This table displays statistically significant (p-value < 0.05) increased IIEF after combination (20.5 ± 3.4) when compared with IIEF after tadalafil (19.1 ± 2.9. (MW: Mann Whitney U test; HS: p-value < 0.05 is regarded as highly significant).