Nardil (Phenelzine): Uses, Side Effects, Warnings, & More

What Is Nardil (Phenelzine)?

Nardil is a type of antidepressant medication known as a monoamine oxidase inhibitor (MAOI). These drugs work by helping to keep serotonin in the brain, which in turn, increases mood. Nardil is most effective in those experiencing a combination of depression and anxiety, often called ‘atypical depression,’ and is usually only given after trying a more conventional antidepressant first. Nardil is not approved for children under the age of 16.^1,2

How Does Phenelzine Work?

Phenelzine works by acting on a chemical known as monoamine oxidase (MAO). Monoamine oxidase removes chemicals from the brain that make us feel happy, such as serotonin and norepinephrine. Phenelzine blocks MAO so that these chemicals can remain in the brain and improve depression symptoms. ¹

What Is Phenelzine Used to Treat?

Phenelzine is FDA-approved for use in treatment-resistant depression and atypical depression, which is depression mixed with symptoms of anxiety, phobia, or hypochondria.². For a medication to be FDA-approved means that it has undergone a rigorous evaluation process by the U.S. Food and Drug Administration (FDA) and has been deemed safe and effective for its intended use. Phenelzine is not considered a first-line treatment for most types of depression, meaning it is only started after a different medication has been shown not to be effective. It is not approved for children and adolescents ages 16 and younger.¹

Phenelzine can be potentially useful in anxiety disorder, but this indication is not FDA-approved.^1,2,3 Non-FDA-approved indications are called ‘off-label’ and mean that healthcare professionals may prescribe the medication for uses based on clinical judgment and emerging evidence, even though they might not have gone through the same rigorous testing and approval process as the medication’s primary, on-label use.

Phenelzine Warnings & Precautions

When taking phenelzine, it’s important to be aware of potential interactions with certain foods and medications that can lead to dangerous increases in blood pressure. These interactions can result in dangerously high blood pressure, characterized by symptoms like severe headache and rapid heartbeat.

Additionally, phenelzine can cause side effects such as dizziness, drowsiness, blurred vision, dry mouth, and changes in sexual function. It’s essential to follow your doctor’s guidance, report any unusual or severe side effects, and avoid abrupt discontinuation of the medication. If you experience suicidal thoughts or behavior, especially when starting the medication, inform your healthcare provider promptly.¹

Precautions for taking phenelzine include:¹

• Hypertensive crisis risk: Phenelzine can interact with foods high in tyramine, leading to a dangerous increase in blood pressure, known as a hypertensive crisis. This includes aged cheeses, certain meats, and alcoholic beverages.
• Drug interactions: Phenelzine can interact with a wide range of medications, potentially causing serious side effects or reduced effectiveness. Inform your healthcare provider and pharmacist about all medications you are taking, including non-prescription medications (e.g. over-the-counter medications).
• Serotonin syndrome: Taking phenelzine with other medications that affect serotonin levels can lead to serotonin syndrome, characterized by symptoms like confusion, rapid heart rate, and muscle stiffness.
• Withdrawal symptoms: Abruptly stopping phenelzine can result in withdrawal symptoms. It’s important to reduce the dose under medical supervision gradually.
• Suicidal thoughts: Like other antidepressants, phenelzine may increase the risk of suicidal thoughts, especially in young adults. Close monitoring is required, especially at the start of treatment.
• Medical conditions: Inform your doctor about pre-existing medical conditions, including heart problems, liver disease, kidney disease, and seizures, as they can impact the safety of phenelzine use.
• Pregnancy and breastfeeding: The risks and benefits of using phenelzine during pregnancy and breastfeeding should be discussed with a healthcare provider.
• Side effects: Phenelzine can cause side effects like dizziness, drowsiness, blurred vision, dry mouth, and changes in sexual function. Inform your provider or pharmacist about any severe or persistent side effects.

Interactions With Phenelzine

One of the most concerning interactions is with tyramine-rich foods and beverages. Consuming foods high in tyramine, such as aged cheeses, cured meats, and some alcoholic beverages, can lead to a dangerous increase in blood pressure. Additionally, the use of other antidepressant medications, particularly selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), can result in serotonin syndrome, a potentially life-threatening condition characterized by excessive levels of serotonin.

Given these potentially harmful interactions, individuals prescribed phenelzine should maintain open communication with their healthcare provider, disclosing all medications (including over-the-counter medications), substances, and herbs they are using to ensure a safe and effective treatment regimen.¹

10 substances you should avoid while taking phenelzine include:¹

• Certain medications (e.g., SSRIs, SNRIs): Combining phenelzine with other antidepressants, like selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), can lead to serotonin syndrome—a serious condition caused by excessive serotonin levels that results in symptoms such as confusion and rapid heart rate.
• Tyramine-rich foods (e.g., aged cheese, cured meats): Phenelzine inhibits the breakdown of tyramine, a compound found in foods like aged cheeses and cured meats. Consuming these foods while on phenelzine can lead to a sudden and dangerous increase in blood pressure, known as hypertensive crisis.
• Alcohol: Drinking alcohol while taking phenelzine can increase the risk of drowsiness, dizziness, and low blood pressure.
• Cold and allergy medications: Some over-the-counter cold and allergy medications contain ingredients that can interact with phenelzine, potentially leading to increased blood pressure or other adverse effects.
• Decongestants: Decongestant medications, often found in cold and allergy remedies, can have stimulating effects that may worsen the side effects of phenelzine, such as increased heart rate and blood pressure.
• Appetite suppressants: Phenelzine’s interaction with appetite suppressants can result in elevated blood pressure and heart rate.
• Certain herbal supplements: Herbal products like St. John’s wort and ginseng can impact serotonin levels and potentially interact with phenelzine, leading to symptoms like serotonin syndrome or other adverse effects.
• Caffeine: High caffeine intake can enhance the stimulant effects of phenelzine, potentially leading to increased heart rate and restlessness.
• Narcotic pain medications: Opioid pain medications can interact with phenelzine, causing increased sleepiness.
• Blood pressure medications: Combining phenelzine with certain blood pressure medications can lead to unpredictable changes in blood pressure levels.

Side Effects of Phenelzine

Phenelzine can lead to several side effects, including dizziness, drowsiness, blurred vision, dry mouth, and changes in sexual function.¹ While these effects may persist throughout the course of treatment, they can often become more manageable over time as the body adapts to the medication. It’s important to note that these side effects are distinct from temporary effects that individuals might experience as their body adjusts to phenelzine, which might include initial increases in anxiety, restlessness, or insomnia.^1,2,3

Common Side Effects of Phenelzine

Common side effects of phenelzine encompass dizziness, drowsiness, blurred vision, dry mouth, and sexual function changes. While some individuals might not require medical attention for these effects as they tend to diminish over time, close monitoring is crucial to assess their impact and to address any severe or persistent symptoms promptly. It’s recommended to maintain a dialogue with a healthcare professional, including your prescriber and pharmacist, to ensure proper management and support during phenelzine treatment.

Common side effects of phenelzine include:*

• Dizziness
• Drowsiness
• Blurred vision
• Dry mouth
• Changes in sexual function (decreased sexual desire, erectile difficulties, and delayed ejaculation)

*This is not a complete list of possible side effects with Nardil. You should talk with your healthcare prescriber or pharmacist about the potential risks of phenelzine before starting the medication.

Serious Side Effects of Phenelzine

While phenelzine can offer relief from depression, it’s important to remain vigilant about potential serious side effects that can arise. These effects may require immediate medical attention and can include severe headaches, rapid heartbeat, difficulty breathing, hallucinations, and signs of an allergic reaction.¹ Seeking prompt medical care is vital if any of these symptoms occur to ensure appropriate intervention and safety during the course of treatment.

Serious side effects of phenelzine may include:*¹

• Severe headaches
• Seizures
• Muscle spasms
• Increase in blood pressure
• Difficulty breathing
• Hallucinations

*All medications, including phenelzine, can cause side effects which can be mild or serious. This is not a comprehensive list of all possible side effects. You should talk with your doctor about any questions you have and to understand the potential side effects and benefits of any medication.

Antidepressant Discontinuation

Antidepressant discontinuation syndrome, also referred to as antidepressant withdrawal, can occur when a person abruptly stops or significantly reduces their use of certain antidepressant medications. The symptoms can vary widely and may include dizziness, nausea, anxiety, irritability, flu-like symptoms, and “brain zaps,” which are described as brief electric shock sensations in the head.^1,4

Immediate medical care is required when discontinuation syndrome symptoms manifest. Abruptly stopping antidepressant medications can trigger these symptoms, which is why a gradual tapering under the guidance of a healthcare provider is recommended when discontinuing antidepressants.¹

Allergic Reactions to Phenelzine

Allergic reactions to phenelzine are possible, though rare. Individuals who have a history of allergies to other drugs, substances, or ingredients may be at a slightly higher risk.⁵ While these reactions are uncommon, if someone experiences symptoms like rash, itching, swelling, severe dizziness, or difficulty breathing after taking phenelzine, immediate medical attention is crucial.⁶ It’s advisable for individuals with a known history of allergies or sensitivities to discuss their concerns with a healthcare provider before starting phenelzine to ensure appropriate monitoring and management.

Allergic reactions to phenelzine may include:^1,6

• Rash or hives
• Itching or swelling, especially of the face, lips, or tongue
• Severe dizziness or lightheadedness
• Difficulty breathing or shortness of breath
• Chest tightness or chest pain
• Rapid or irregular heartbeat
• Severe nausea, vomiting, or diarrhea
• Unexplained fever
• Feeling unusually weak or tired
• Yellowing of the skin or eyes (jaundice)

If someone experiences allergic reactions to phenelzine, they should seek immediate medical attention. Your healthcare provider will assess the severity of the reaction and determine whether phenelzine needs to be discontinued. Depending on one’s condition and needs, alternative medication options or treatment strategies can be explored to manage depression while prioritizing safety effectively.

Phenelzine Dosages for FDA-Approved Treatment

Dosages of phenelzine can vary significantly for each individual based on factors such as the severity of depression, response to the medication, and any potential interactions with other drugs. The typical dosage range for phenelzine is around 15 to 90 milligrams per day, divided into two to three doses.¹ Individualized dosing is crucial, and healthcare providers often start with lower doses and gradually increase them while closely monitoring the patient’s response and any side effects. Factors that can affect dosages include age, medical history, other medications being taken, and any pre-existing conditions.

When a medication is FDA-approved, it means that the U.S. Food and Drug Administration has thoroughly evaluated its safety and efficacy through rigorous clinical trials and scientific research. The approval signifies that the medication has met the FDA’s standards for quality, safety, and effectiveness for its intended use. The FDA reviews data from clinical trials to assess the medication’s benefits, potential risks, and any potential interactions with other drugs.

Phenelzine Forms & Strengths

Phenelzine is typically available in tablet form and comes in various strengths, ranging from 15 to 90 milligrams.¹ The choice of the appropriate form and strength is determined by factors such as the specific disorder being treated, the age of the patient, and the diagnosis being addressed. Notably, the severity of symptoms is not directly related to the dosage. The medication is not available in extended-release, delayed-release, or sustained-release formulations.

When selecting one form over the other, prescribers consider factors such as the patient’s medical history, response to previous treatments, and the potential for interactions with other medications. Dosages may vary based on the type of disorder being treated, with higher doses sometimes required before patients see a response.¹ The onset of action for phenelzine can take several weeks, regardless of the chosen form or strength, as the medication needs time to have its full therapeutic effect.

Phenelzine is available in the following forms and strengths:

• 15 milligram (mg) oral tablet

Take phenelzine exactly as prescribed by your healthcare provider. Phenelzine should be taken at the specified times and in the recommended dosages. For tablet forms, follow the instructions provided by your healthcare professional, which may include splitting doses throughout the day. It’s important to adhere to your prescribed regimen to ensure the medication’s effectiveness and minimize the risk of side effects.

How Should I Take Phenelzine?

Phenelzine should be taken exactly as directed by your prescriber. It is important to follow the prescribed dosage and timing to ensure the medication’s effectiveness and safety. To take phenelzine, swallow the tablet(s) whole with a glass of water. It can be taken with or without food, but it’s often recommended to take it with meals to help reduce potential stomach upset. Certain foods should be avoided, such as those high in protein, foods that have been pickled or smoked, or foods that have been fermented.¹

Following your prescriber’s instructions is essential for successful treatment. If you have any questions about how to take phenelzine or are unsure about any aspect of your treatment plan, consult your healthcare provider or pharmacist for clarification.

What Should I Do If I Miss a Dose of Phenelzine?

If you miss a dose of phenelzine, take it as soon as you remember unless it’s close to the time for your next scheduled dose. In that case, skip the missed dose and resume your regular dosing schedule.¹ Do not double up on doses or take extra doses to catch up. Abruptly stopping or altering the dosing schedule can lead to disruptions in the medication’s effectiveness and may result in withdrawal symptoms or adverse effects.

Can You Overdose on Phenelzine?

Yes, it is possible to overdose on phenelzine, and doing so can have serious consequences. Taking more than the prescribed amount can lead to an excessive buildup of the medication in your system, potentially causing severe side effects or complications. Signs and symptoms of a phenelzine overdose can vary and may include severe dizziness, confusion, hallucinations, agitation, rapid heartbeat, high blood pressure, severe headache, and even loss of consciousness.¹

What Should You Do If You Take Too Much Phenelzine?

If you suspect that you or someone else may have overdosed on phenelzine, seek immediate medical attention or contact a poison control center (800-222-1222). It is important to inform your prescriber and pharmacist about all medications, including phenelzine, that you or the affected individual is taking, as well as the estimated amount of the medication that was ingested. Quick medical intervention can help manage an overdose and prevent serious health risks.

Questions to Ask Your Healthcare Provider About Nardil (Phenelzine)

When consulting with your doctor or psychiatrist about phenelzine, you may have questions. And if you need to find an additional or different provider, online psychiatry services may be a good option for you. Asking questions can help you and your provider clarify important information before beginning your medication.

Questions to ask your care team about phenelzine include:

• What are the potential side effects of phenelzine that I should be aware of?
• Are there any specific dietary restrictions I should follow while taking phenelzine?
• Can I continue taking my other medications or supplements while on phenelzine?
• How long does it usually take for phenelzine to start working?
• What’s the recommended dosage of phenelzine for my condition, and how should I take it?
• Are there any alternative treatment options for my depression that we should consider?
• Can phenelzine affect my daily activities, such as driving?
• If I miss a dose of phenelzine, what should I do?
• Are there any potential long-term effects or complications associated with taking phenelzine?
• How will phenelzine interact with any pre-existing medical conditions I may have?
• Is there a specific plan for discontinuing phenelzine if needed, and what should I expect during the process?
• Can I participate in therapy or counseling alongside phenelzine treatment to enhance its effectiveness?
• Are there any signs that would indicate phenelzine isn’t working for me or that I need a different treatment approach?
• How will phenelzine impact my overall well-being and quality of life?

In My Experience

In my experience, discussing Nardil (phenelzine) treatment with your prescriber and pharmacist is a pivotal step toward understanding its potential benefits and risks. This comprehensive guide sheds light on crucial aspects of phenelzine, including its interactions, potential side effects, and dosing guidelines, but does not replace having a conversation with a provider.

When it comes to depression and its treatments, there are lots of factors to consider as individual responses will vary, and working closely with a provider is essential to optimize a treatment program. The outlook for clients undergoing phenelzine treatment can be promising when approached with diligence and medical supervision. Adhering to prescribed regimens and maintaining an open line of communication with your healthcare providers, including your pharmacists, can yield positive results.

For Further Reading

• How to Get Antidepressants: Everything You Need to Know – Choosing Therapy
• How Do Antidepressants Make You Feel? Possible Side Effects & Changes
• Types of Depression: 15 Common Depressive Disorders
• Depression Resources For Everyone