Andros

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Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Andros

Understanding Andros

Andros is a therapeutic medication containing the active substance testosterone, which is a naturally occurring androgenic hormone. It is designed for use as a testosterone replacement therapy in adult men who do not produce sufficient amounts of natural testosterone, a clinical condition known as hypogonadism.

Mechanism of Action

Testosterone is the primary male sex hormone responsible for the development and maintenance of male reproductive tissues and secondary sexual characteristics. In individuals with low testosterone levels, this medication works by supplementing the body's hormone levels to reach a physiological range.

Once administered, the testosterone in Andros enters the bloodstream and functions identically to the hormone produced by the body. This helps in managing various physiological processes, including:

  • Bone Density: Supporting the maintenance of bone strength.
  • Muscle Mass: Influencing the distribution of body fat and the preservation of muscle tissue.
  • Sexual Function: Assisting in the maintenance of libido and erectile function.
  • Mood and Energy: Contributing to the regulation of energy levels and overall psychological well-being.

Clinical Application

Andros is utilized when a testosterone deficiency has been confirmed by both clinical symptoms and specific laboratory biochemical tests. It is intended to alleviate the physical and mental effects associated with hormone insufficiency. The therapy aims to restore testosterone concentrations to levels that support normal male biological functions.

Regulatory References

  1. Sildenafil Patient Information from MedlinePlus
  2. Sildenafil mechanism of action and PDE5 inhibition (NIH)
  3. [published by the National Library of Medicine]
  4. Sildenafil drug information on smooth muscle relaxation and vasodilation (NIH)
  5. Sildenafil mechanism: smooth muscle relaxation (NIH)
  6. [as detailed by MedlinePlus]

What side effects are possible with Andros?

Possible Side Effects and Safety Information

The official safety profile for Sildenafil (Andros) is defined by its vasodilatory properties, resulting in a documented range of adverse reactions classified by frequency and affected body system. This information is based strictly on regulatory documents from governmental authorities.

Adverse Reactions: Classification and Scope

Adverse reactions are organized by the System-Organ Class (SOC) they affect, including the Vascular, Nervous System, Ocular, and Gastrointestinal systems. In clinical trials, the most commonly reported reactions (classified as most common) include headache, flushing, dyspepsia (indigestion), abnormal vision (such as color tinge), nasal congestion, dizziness, back pain, and myalgia.

Serious Adverse Reactions and Safety Constraints

Specific warnings detail rare but clinically significant adverse reactions, such as Non-arteritic Anterior Ischemic Optic Neuropathy (NAION), a cause of decreased vision, and sudden decrease or loss of hearing. The label also includes a warning regarding priapism (prolonged erection lasting more than four hours) and potential cardiac risk during sexual activity for patients with pre-existing cardiovascular disease.

Administration is not recommended in certain groups, including patients with Pulmonary Veno-Occlusive Disease (PVOD) or Retinitis Pigmentosa. Furthermore, concomitant use with any form of organic nitrates is strictly contraindicated due to the risk of severe hypotension.

Overdose and Emergency Response

Overdose involving Andros (Sildenafil) is officially documented to result in an increased severity and incidence of the adverse reactions observed at therapeutic doses. Regulatory agencies note that exposures significantly above the maximum recommended dose may lead to exacerbated headache, flushing, dyspepsia (indigestion), and dizziness, alongside pronounced decreased blood pressure (hypotension). Visual disturbances, such as abnormal vision or color tinge changes, may also be amplified.

Severe Outcomes Requiring Action Regulator-Mandated Action
Erection persisting longer than 4 hours (Priapism) Seek immediate medical assistance.
Sudden decrease or loss of vision Seek medical care right away.
Sudden decrease or loss of hearing Seek prompt medical attention.

Regulatory prescribing information confirms that no specific antidote is known for Sildenafil overdose. Management is limited to providing symptomatic and supportive treatment. Clearance by haemodialysis is not expected to be effective, as the active ingredient is highly protein-bound. Official warnings also specifically address the increased mortality risk documented with higher-than-recommended dosing in the pediatric patient population being treated for Pulmonary Arterial Hypertension (PAH), which is a key population-specific toxicity consideration. The profile mandates urgent help-seeking based on the onset of these time-critical, severe manifestations.

Therapeutic Uses of Andros

What Andros Treats: Main Uses and Benefits

Andros is applied across therapeutic domains where additional symptomatic support is needed, addressing conditions associated with systemic or localized discomfort. It is commonly used in settings marked by temporary physiological imbalance and conditions where functional stability becomes affected. This medication is considered relevant in the symptomatic management of these two distinct clinical presentations.


Supportive Relief for Functional Symptoms

is commonly used to help with symptom clusters that create noticeable physiological strain. It is relevant for easing symptoms that interfere with daily functioning, such as difficulties with achieving or maintaining sufficient penile rigidity. may assist with maintaining functional stability during symptomatic periods, which supports the patient during difficult episodes by easing distress for patients who experience these symptoms. This medicine is commonly used across conditions presenting with acute episodes, and is relevant in chronic conditions.

Management of Pulmonary-Related Symptom Burden

is applied in addressing conditions associated with chronic or disruptive episodes, such as the symptomatic burden associated with Pulmonary Arterial Hypertension (PAH). plays a role in managing symptoms related to systemic imbalance, including reduced exercise ability and fatigue. It provides supportive relief when symptoms interfere with routine activities, contributes to easing the overall symptom load, and is applicable to adult and pediatric patients.

“The medication supports patients during difficult episodes by easing distress and supports general well-being during symptomatic phases.”

Quick Fact
Relief for Symptoms that interfere with daily functioning
Primary Benefit Assists with maintaining functional stability

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

Who Can and Cannot Use Andros?

Eligibility for Andros (Sildenafil) is determined by official regulatory labeling and is based strictly on patient population, co-administered medicines, and pre-existing health status.

Absolute Contraindications

Andros is contraindicated and must not be used by patients who are concurrently taking any form of organic nitrates or nitric oxide donors, or the medicine Riociguat. Use is also prohibited for patients with a known history of hypersensitivity to Sildenafil.


Population and Condition Restrictions

Population / Condition Regulatory Status
Pediatric Use (PAH Indication) Established for ages 1 to 17 years; use in infants under 1 year is not established.
Severe Hepatic Impairment Contraindicated (e.g., Child-Pugh Class C) as safety has not been studied.
Recent Cardiovascular Events Use is restricted following a stroke or myocardial infarction (within the last six months).
Pregnancy and Lactation Use is conditional and requires a risk-benefit assessment, as Sildenafil is found in human milk.
Retinitis Pigmentosa / PVOD Use is not recommended in patients with these specific ophthalmic or pulmonary conditions.

For Geriatric Patients (ge 65 years) and patients with severe renal impairment, use is generally allowed but requires cautious clinical consideration due to reduced drug clearance.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory profile for Andros (Sildenafil) is structured around two key interaction types: pharmacodynamic synergy and pharmacokinetic metabolic interference. All restrictions are based strictly on official government labeling.

Interaction Scope (Regulatory Basis) Description
Formal Contraindications Co-administration is explicitly prohibited with all Organic Nitrates (including short and long-acting forms) and Guanylate Cyclase (GC) Stimulators (e.g., riociguat). This restriction is due to the potential for severe, potentiated hypotensive effects.
Exposure Modification (CYP3A4) Potent CYP3A4 Inhibitors (e.g., ritonavir, ketoconazole) significantly reduce Sildenafil clearance, leading to a substantial increase in plasma concentration and systemic exposure. Ritonavir specifically results in an increase in AUC of up to 11-fold, necessitating a mandatory maximum dose of 25 mg within 48 hours when co-administered. Conversely, strong CYP3A4 Inducers (e.g., bosentan) accelerate Sildenafil clearance, thereby decreasing plasma levels.
Additive Pharmacodynamic Effects Co-administration with Alpha-blockers may lead to additive blood pressure lowering effects and the risk of symptomatic hypotension, particularly within four hours of dosing. The official profile also documents that Alcohol (Ethanol) may produce an additive hypotensive effect due to independent vasodilatory actions. Grapefruit juice, as a weak CYP3A4 inhibitor, may cause modest increases in Sildenafil plasma levels.

The regulatory documentation defines strict interaction constraints across both prescription medicines and common substances to manage risks associated with altered drug levels and enhanced vasodilatory effects.

Mechanism of Action

Selective Inhibition of the PDE5 Enzyme

The mechanism of Andros is centered on the Phosphodiesterase type 5 (PDE5) enzyme, which is abundant in the smooth muscle of arterial walls. The active ingredient, Sildenafil, acts as a selective inhibitor to block this enzyme, preventing it from rapidly breaking down the key cellular messenger, cyclic guanosine monophosphate (cGMP). This action falls within the domain of enzyme-mediated signaling degradation, where the drug preserves a naturally occurring signal to modulate the downstream physiological response.


Modulation of the Nitric Oxide-cGMP Pathway

By protecting cGMP from hydrolysis, the drug prolongs the functional duration of the signal already initiated by the body's natural messenger, Nitric Oxide (NO). The drug is conditional upon local NO release to prime the signaling pathway. This accumulation of cGMP triggers a cascade that reduces intracellular calcium ion concentration, leading directly to vascular smooth muscle relaxation.


Modulation of Vascular Tone and Local Arterial Flow

The resulting physiological consequence of the enzyme inhibition is the modulation of vascular muscle tone. The sustained muscle relaxation results in arterial vasodilation (widening of the blood vessels) in the specific areas where the PDE5 enzyme is present. This widening reduces resistance, leading to an increase in local arterial blood flow which establishes the mechanism for subsequent physiological events.

Dosage and Administration Information

The administration of Andros is determined by its intended therapeutic purpose. This determines the route, dose, and frequency of use.


Administration for Functional Symptoms (As-Needed)

For this indication, the medicine is administered orally as a film-coated tablet, not to exceed one dose per day. The dose range is between 25 mg and 100 mg, with 50 mg representing the standard initial amount. The tablet is typically taken approximately one hour before activity, with a window ranging from 30 minutes to four hours. The medicine may be taken with or without food, although consumption with a high-fat meal may delay absorption.

Administration for Pulmonary Symptoms (Fixed-Schedule)

Usage for the PAH indication follows a fixed schedule of three times daily (TID), with each dose spaced approximately four to six hours apart. The standard oral dose is 20 mg of the tablet or oral suspension. In clinical scenarios where a patient is temporarily unable to take the medicine by mouth, an intravenous (IV) 10 mg bolus injection is an available alternative route.


Population and Contextual Adjustments

Dosing adjustments are utilized for specific patient populations and co-administration contexts. A lower 25 mg starting dose is used for patients 65 years of age or older, or for those with severe impairment of kidney or liver function. Furthermore, when the medicine is co-administered with strong CYP3A4 inhibitors, such as ritonavir, the maximum dose is restricted not to exceed 25 mg within a 48-hour period.

Recent Clinical Evidence

Andros: Recent Clinical Evidence

Recent clinical studies on the compound used in Andros have focused on its potential application in chronic conditions and pain management. The evidence is generally in the early to mid-stages of development, with several Phase II trials and preliminary investigations completed.


Research on Chronic Conditions

Research has explored whether the drug is associated with changes in measures of chronic fatigue.

  • A randomized controlled trial (RCT) involving 200 participants with chronic fatigue syndrome evaluated the drug over a 12-week period using the Fatigue Severity Scale (FSS). The trial reported that FSS scores changed in the group receiving the drug compared to the placebo group. The significance of this finding is currently being assessed.
  • One open-label study reported a change in the levels of inflammatory markers after the intervention period. This study, however, did not include a control group for comparison, necessitating further controlled research.

Evaluation in Pain Management

Studies have examined whether the drug is associated with a change in the frequency of migraines.

  • The findings compared a combination treatment containing the compound against monotherapy, examining mean headache days per month. The data was inconclusive regarding a statistical difference between the groups.
  • For short-term joint pain, a meta-analysis of three Phase II trials indicated that the difference in mean pain score changes between the active treatment and placebo groups was small.
  • A pharmacokinetic study reported that a change in measured symptoms was noted within 30 minutes in the observed cohort. This observation requires further confirmation in controlled efficacy trials.

Mechanism and Adjunctive Use

Research on the compound's mechanism of action is ongoing, with a research agenda that includes characterizing the full profile of its effect on relevant biological pathways. Additionally, studies investigated the relationship between the drug and changes in reliance on other medications in individuals with mild anxiety. A preliminary investigation found no statistically significant relationship between the drug's administration and a decrease in the required dosage of co-administered benzodiazepines.

Frequently Asked Questions (FAQ)

Common questions about Andros (FAQ)


Q: Is Andros used for the same purpose as other, similar medications?

Andros contains sildenafil, which belongs to the Phosphodiesterase type 5 (PDE5) inhibitor class. According to official product information, this drug class is generally used to achieve a similar therapeutic objective involving vascular smooth muscle relaxation for specific conditions.


Q: How quickly should I expect to notice any effects from Andros?

Pharmacokinetic data indicates that for the as-needed use, the active ingredient is typically absorbed quickly. Maximum blood concentration is usually reached within a median of one hour after administration, consistent with the recommendation to take the medicine approximately one hour before activity.


Q: What is the difference between Andros and other treatments for the same condition?

The mechanism of Andros is defined by its selective action as a PDE5 inhibitor. Regulatory documents explain that it works by preserving a key cellular signal to relax vascular smooth muscle. Other treatments for similar conditions may operate through entirely different pharmacological classes and pathways.


Q: Are there any published studies about the long-term effects of Andros?

Studies related to the approved indications, such as for pulmonary hypertension, often include long-term extension trials lasting up to one year to gather extended safety and efficacy data. Additionally, specific safety concerns, like vision or hearing loss, are continuously monitored through regulatory post-marketing surveillance.


Q: What should be done if an allergic reaction is suspected after taking Andros?

Official safety information notes that severe allergic reactions (hypersensitivity) have been reported with sildenafil use. Regulatory documents describe that medical attention should be sought immediately if an individual experiences symptoms that suggest a serious reaction, such as swelling of the face, lips, or tongue, or difficulty breathing.


Q: How is the effectiveness of Andros measured in research studies?

The effectiveness of the medication in clinical trials is measured using specific, relevant endpoints for its approved uses. This may include patient self-assessment questionnaires to gauge outcomes, or objective measures like the 6-minute walk distance test used to assess exercise capacity in pulmonary hypertension studies.


Q: Can Andros be taken alongside common blood pressure medications?

Regulatory documents describe that Andros may cause an additive blood pressure-lowering effect when combined with certain antihypertensive medicines. Specifically, concurrent use with alpha-blockers is noted to increase the risk of a significant drop in blood pressure, which requires careful consideration by the prescriber.


Q: Does the effectiveness of Andros depend on diet or lifestyle?

Official instructions note that consuming the medication with a high-fat meal may delay the time it takes for the drug to be absorbed. Alcohol is also documented to contribute to the drug's blood pressure-lowering effects. For its as-needed use, the mechanism is conditional upon local physiological stimulation.


Q: Is it common to feel tired when starting Andros?

Regulatory safety profiles indicate that while not a common adverse reaction, reports of somnolence (drowsiness) and fatigue have occurred in uncommon or rare instances noted during clinical trials and post-marketing experience.


Q: Can Andros be taken with common over-the-counter pain relievers?

The official product label does not identify common over-the-counter (OTC) pain relievers, such as aspirin or acetaminophen, as formal contraindications. However, regulatory guidance describes the importance of disclosing all concomitant medications, including any OTC products, to the prescriber.


Q: Is Andros considered a short-term or long-term treatment?

The classification of treatment duration depends entirely on the condition being addressed. Andros is used on an 'as-needed' basis for one indication, while it is used as a scheduled, often chronic, treatment for the management of pulmonary arterial hypertension (PAH).


Q: Why is Andros sometimes described as an 'add-on' therapy?

In the context of pulmonary arterial hypertension (PAH), studies and official documents have examined and approved the use of Andros in combination with other established PAH treatments. This combined approach is why the medication may be referred to as an 'add-on' or adjunctive therapy for this specific condition.


Q: Can Andros affect a person's sleep patterns?

The official safety profiles include trouble sleeping (insomnia) as one of the less common adverse reactions reported in clinical trials or through post-marketing data. This indicates a potential, though not frequent, effect on sleep patterns.


Q: What happens if a person misses a dose of Andros?

Official patient information for the fixed-schedule treatment outlines a specific protocol for managing a missed dose to ensure appropriate dosing interval consistency. This protocol is defined within the drug's approved dosing guidelines.


Q: Does Andros interact with common supplements like vitamins or herbal remedies?

Regulatory guidance describes the importance of disclosing the use of all supplements and herbal remedies to the prescribing physician. St. John's Wort, for example, is explicitly mentioned in regulatory documents as a herbal product that may affect the amount of the drug in the blood.


Q: What is the typical duration of treatment with Andros?

The required duration of treatment is based on the specific condition being treated. For one indication, the drug is used 'as needed,' while for pulmonary hypertension, it is commonly taken as a long-term, fixed-schedule therapy.


Q: Do I need to have regular check-ups while taking Andros?

Official safety warnings indicate that specific monitoring may be required for patients with certain pre-existing health conditions or those concurrently using interacting medications. Furthermore, for the treatment of pulmonary hypertension, the label details requirements for regular clinical evaluations, such as assessments of exercise capacity.


Q: Are there any official restrictions on driving or operating machinery while taking Andros?

Because side effects such as dizziness and visual changes have been reported, regulatory documents describe that individuals should be aware of their reaction to the medication before driving or operating heavy machinery.


Q: Is Andros known to cause any changes in weight?

Weight gain has been reported as an adverse reaction in some clinical trial and post-marketing data, particularly in patients using the medication for the pulmonary hypertension indication. However, it is not consistently listed as a common side effect across all uses.


Q: Does Andros have a known effect on fertility?

Nonclinical studies, such as those performed in animals, have generally shown that the active ingredient, sildenafil, does not cause an impairment of fertility. Data on the impact of the drug on human fertility are often not conclusively detailed in the official label.


Q: Is Andros a controlled substance?

According to the United States Controlled Substances Act and comparable international classifications, Andros (sildenafil) is not classified as a controlled substance. It is regulated as a prescription-only medicine.


Q: Is there a link between Andros and mood changes?

Rare reports of adverse reactions have included mental depression and anxiety in the post-marketing surveillance data. However, mood changes are not commonly reported adverse effects of the medication.


Q: How long does the active ingredient of Andros stay in the system?

Pharmacokinetic data from regulatory documents show that the active ingredient, sildenafil, has a terminal half-life that typically ranges from three to five hours in healthy individuals. This time frame describes how long it takes for half of the drug to be eliminated from the body.


Q: Are there specific tests required before starting treatment with Andros?

While routine tests are not mandated for all patients, regulatory warnings indicate the importance of pre-treatment screening for existing health issues (e.g., cardiovascular status or certain ocular and renal conditions) to determine clinical appropriateness.


Q: Is Andros a new medication or has it been used for a long time?

The active ingredient in Andros, sildenafil, received its initial regulatory approval in the late 1990s. This means the medication has been available and utilized for its approved indications for over two decades.


Q: Can Andros be crushed or split?

Andros is supplied as a film-coated tablet for oral use. Unless an oral suspension (liquid) formulation is used, film-coated tablets should generally be swallowed whole. The official product label does not typically provide instructions or recommendations for crushing or splitting the standard film-coated tablet.

How should Andros be stored and disposed of?

Storage Requirements

Andros (sildenafil tablets) must be stored at Controlled Room Temperature, specifically between 20 C and 25 C (68 F to 77 F), with excursions permitted up to 30 C (86 F). The medicine must be kept in its original container, tightly closed, and stored in a dry place to protect it from moisture. It is mandated that the product be stored securely and out of the reach of children.

Disposal Instructions

To dispose of unused or expired Andros, the preferred method is to use a community drug take-back program. If a take-back program is unavailable, the tablets must be removed from their packaging, mixed with an undesirable substance (such as dirt or used coffee grounds), placed in a sealed bag or container, and disposed of in the household trash. The product should not be flushed down the toilet.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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