Drugs Used for Protein Energy Malnutrition (PEM)

December 5, 2025 •

4 min read

According to the World Health Organization (WHO), severe acute malnutrition (SAM) affects nearly 20 million children globally and is a leading cause of childhood mortality. While nutritional rehabilitation is the cornerstone of treatment for protein energy malnutrition (PEM), specific drug therapies are essential to manage complications and support recovery. These medications address underlying infections, correct metabolic derangements, and stimulate appetite to aid nutritional recovery.

Quick Summary

This article discusses the pharmacological agents and supportive medications used to treat protein energy malnutrition, including antibiotics for infection, micronutrient supplements for deficiencies, and appetite stimulants for anorexia. It outlines the phased approach to managing PEM and highlights the importance of concurrent nutritional therapy. The content also covers specific drug regimens for both children and adults.

Key Points

Antibiotics are essential for infection: Since malnourished patients have compromised immune systems and may not show typical signs of infection like fever, broad-spectrum antibiotics are routinely given, especially in severe cases.
Micronutrients correct deficiencies: Vitamins (A, D, E, B-complex) and minerals (zinc, potassium, magnesium) are crucial supplements, though iron is typically withheld initially to avoid exacerbating infections.
Appetite stimulants aid intake: In adults with secondary PEM or cachexia, drugs like megestrol acetate or dronabinol may be used to increase appetite and calorie consumption.
Hormonal agents target muscle wasting: Anabolic steroids or ghrelin agonists may be used in specific cachexia syndromes associated with chronic diseases like cancer or renal failure to build lean body mass.
Oral rehydration is specialized: Malnourished patients with diarrhea require a special oral rehydration solution (e.g., ReSoMal) with lower sodium and higher potassium content to correct fluid and electrolyte imbalances safely.
Treatment is multi-phased: The management of severe PEM involves stabilization (correcting urgent metabolic issues and infection) followed by rehabilitation (promoting catch-up growth).
Refeeding syndrome risk must be managed: Rapid refeeding after starvation can cause fatal shifts in electrolytes and fluids; therefore, feeding must be introduced cautiously and gradually.

The Pharmacological Approach to Protein Energy Malnutrition

Treating protein energy malnutrition (PEM) is a complex process that relies primarily on nutritional rehabilitation but also incorporates specific drug therapies to address the associated medical complications. The choice of medication depends heavily on the patient's age, the severity of malnutrition, and the presence of underlying health issues. Drug therapy is typically used to stabilize the patient, treat any infections, and correct severe metabolic imbalances that are common in malnourished individuals.

Drugs for Treating Infections

Infections are a frequent and dangerous complication of PEM, as a compromised immune system can mask the typical signs like fever. For this reason, broad-spectrum antibiotics are often administered, particularly in cases of severe acute malnutrition (SAM), even without overt signs of infection. The specific antibiotic regimen varies by age and the presence of complications.

Pediatric Antibiotic Regimens for PEM

For children with uncomplicated SAM, oral amoxicillin is a recommended first-line treatment. A typical regimen lasts for seven days and may be administered as an outpatient.

For children with complicated SAM, a more aggressive approach with parenteral (intramuscular or intravenous) antibiotics is necessary. Common combinations and medications may include:

Ampicillin and Gentamicin: Often given initially for inpatient treatment of complicated SAM. A treatment course may begin with parenteral administration before transitioning to an oral antibiotic.
Ceftriaxone: A broad-spectrum cephalosporin that may be used for severely ill children, especially if local antibiotic resistance rates are high.
Metronidazole: May be added for severe or persistent diarrhea, which can exacerbate malnutrition, though its efficacy is still under investigation in some contexts.

Micronutrient Supplements

PEM is almost always accompanied by deficiencies in essential vitamins and minerals, which must be corrected carefully during the stabilization and rehabilitation phases. Immediate supplementation is crucial, with iron supplementation typically delayed until the patient is gaining weight to avoid potentially worsening infections.

Common Micronutrient Supplements for PEM:

Vitamin A: May be given as a high-dose supplement early in treatment, especially since deficiency is common and impairs immune function.
Zinc: Supplementation has been shown to reduce the incidence of diarrhea and improve growth rates. Oral or topical zinc may also aid in healing skin lesions common in kwashiorkor.
Folic Acid: A supplement is administered to correct deficiency, which is often present.
Electrolyte-Mineral Mix: Severely malnourished patients have significant deficiencies in potassium, magnesium, and other electrolytes. An electrolyte-mineral solution (like the WHO-recommended ReSoMal) or supplements may be necessary to correct these imbalances and prevent cardiac complications.

Appetite Stimulants and Hormonal Agents

In some cases, particularly in adults with chronic illnesses or cachexia, appetite stimulants and hormonal agents are considered to encourage food intake and counteract metabolic wasting.

Common Appetite Stimulants

Megestrol Acetate: A synthetic progestin that may act as an appetite stimulant, sometimes used in cancer-related cachexia to promote weight gain, though primarily through increased adipose tissue.
Dronabinol (Cannabinoid): A cannabis derivative that may be used to increase appetite and weight gain in patients with cachexia, though evidence for its efficacy in PEM varies.
Cyproheptadine: An antihistamine with appetite-stimulating properties, which has shown some effectiveness in treating cachexia in both adults and children.

Hormonal and Anabolic Agents

These agents aim to increase lean body mass and reverse muscle wasting, especially in chronic conditions associated with cachexia.

Anabolic Steroids (e.g., Oxandrolone): May help increase lean body mass in patients with severe muscle wasting.
Ghrelin Agonists (e.g., Anamorelin): Newer agents that mimic the hunger hormone ghrelin are being investigated to stimulate appetite and improve body weight.
Anti-Myostatin Agents (e.g., Ponsegromab): Monoclonal antibodies targeting myostatin to reverse muscle atrophy are under investigation and have shown promising results in clinical trials for cancer-related cachexia.

Comparison of Medications for PEM Management


Medication Type	Common Examples	Primary Function	Patient Group	Key Considerations
Antibiotics	Amoxicillin, Ampicillin, Gentamicin, Ceftriaxone	Treat and prevent bacterial infections, a common complication of malnutrition.	Children (uncomplicated & complicated SAM), Adults	Use broad-spectrum for severe cases; oral for uncomplicated cases. Monitor for antibiotic resistance.
Micronutrients	Vitamin A, Zinc, Folic Acid, Potassium, Magnesium	Correct severe vitamin and mineral deficiencies that impair immune function and recovery.	Children, Adults	Delay iron supplementation in the acute phase. Individualized dosing is critical.
Appetite Stimulants	Megestrol Acetate, Dronabinol, Cyproheptadine	Stimulate appetite and increase food intake in patients with anorexia or cachexia.	Adults with chronic illness/cachexia, Children	Not suitable for all patients; benefits in PEM must be weighed against side effects.
Hormonal/Anabolic Agents	Oxandrolone, Anamorelin	Promote increase in lean body mass and counteract muscle wasting in cachexia.	Adults (specific conditions like renal failure or cancer)	Often used in specific types of cachexia; not standard for all PEM. Monitor for side effects.
Oral Rehydration Solutions	ReSoMal (WHO Formula)	Correct dehydration and electrolyte imbalances, especially with persistent diarrhea.	Children, Adults	Special formula for malnourished individuals with lower sodium content.

Conclusion: A Multi-faceted Treatment Approach

Drugs used for protein energy malnutrition are a crucial component of a broader, multi-faceted treatment plan. There is no single pill for malnutrition; rather, pharmacological interventions are used to manage the severe, life-threatening complications that arise from a malnourished state. Antibiotics combat opportunistic infections, a major cause of mortality in PEM. Micronutrient supplements address the underlying deficiencies that affect recovery and immune function. Meanwhile, in chronic or complex cases, appetite stimulants and anabolic agents can help drive nutritional intake and reverse wasting. Effective treatment requires not only these medications but also meticulous nutritional support, monitoring, and addressing the social and economic root causes of malnutrition. By strategically combining drugs with proper nutritional and supportive care, healthcare providers can significantly improve outcomes and reduce mortality rates associated with this devastating condition.

Additional Resource

For further reading on the phased approach to managing severe malnutrition, the World Health Organization provides comprehensive technical guidelines: Management of severe acute malnutrition: a systematic review.

Frequently Asked Questions

The primary treatment for protein energy malnutrition is nutritional rehabilitation, which involves reintroducing specialized therapeutic foods and formulas gradually. Drug therapy is used as a supportive measure to treat infections, correct deficiencies, and manage complications.

Severely malnourished individuals, especially children, often have a weakened immune system that prevents them from mounting a typical fever response to infection. Because infections are very common and can be fatal, broad-spectrum antibiotics are given empirically, even if no obvious signs of infection are present.

For complicated cases of severe acute malnutrition (SAM), initial treatment often involves parenteral antibiotics like a combination of ampicillin and gentamicin. Oral amoxicillin is a standard treatment for uncomplicated SAM.

Appetite stimulants, such as megestrol acetate, are sometimes used in adult patients with chronic illness or cachexia to increase food intake. However, their use is more specific to managing cachexia than for typical PEM in resource-poor settings.

Iron supplementation is typically delayed until a severely malnourished patient has passed the initial stabilization phase and has begun to gain weight. Giving iron too early can potentially worsen infections due to oxidative stress.

Refeeding syndrome is a potentially fatal metabolic complication that can occur when a severely malnourished person is fed too quickly. It causes severe fluid and electrolyte shifts, particularly hypophosphatemia. Management involves starting feeding very slowly, closely monitoring electrolytes, and correcting imbalances with supplements.

Hormonal agents like anabolic steroids or ghrelin agonists are sometimes used in specific cases of cachexia associated with chronic illnesses. These drugs are aimed at increasing lean body mass and are not a standard treatment for general PEM.