Pima

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Medically reviewed

Laura Arias

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 Pima

Quick Facts

  • Active Ingredient: Potassium Iodide
  • Drug Class: Antithyroid agent, Expectorant
  • Primary Uses: Protection against radioactive iodine exposure, treatment of hyperthyroidism (overactive thyroid)

What is Pima?

Pima is a brand name for the medication potassium iodide, which is a chemical compound containing iodine. This compound has two primary therapeutic uses in medicine.

First, potassium iodide is used as an antithyroid agent to treat certain cases of hyperthyroidism (overactive thyroid) by helping to suppress the function of the thyroid gland. Second, and perhaps its most recognized application, it is used to protect the thyroid gland from the damaging effects of radioactive iodine.

Mechanism in Radiation Emergencies

In the event of accidental exposure to radioactive iodine—such as during a nuclear power plant incident—Pima is administered to saturate the thyroid gland with non-radioactive iodide. This prevents the thyroid from absorbing the harmful radioactive iodine, reducing the risk of developing thyroid cancer later in life.

Other Uses

Potassium iodide, the active ingredient in Pima, is also sometimes classified and used as an expectorant, which can help to loosen mucus and phlegm in the respiratory system, aiding in the treatment of cough and other respiratory conditions. The drug is available in various forms, including oral solution and tablets, and the specific dosage and form depend on the condition being treated and the patient's age and weight.

What side effects are possible with Pima?

Possible Side Effects and Safety Information

The safety profile for Pima (Pimavanserin) is governed by specific warnings regarding serious and common adverse reactions, as detailed in governmental regulatory documents.

Serious Warnings and Precautions

  • Increased Mortality in Elderly Patients with Dementia-Related Psychosis: Pima, like other atypical antipsychotic medications, carries a Boxed Warning regarding an increased risk of death in older adult patients with dementia-related psychosis. The drug is not approved for the treatment of psychosis associated with dementia unless the hallucinations and delusions are related to Parkinson’s disease.
  • QT Interval Prolongation: Pima can cause a prolongation of the QT interval, which is a heart rhythm abnormality. This effect can lead to serious and potentially fatal irregular heart rhythms, such as Torsade de Pointes. The risk increases when used in patients with a history of QT prolongation, cardiac arrhythmias, or in combination with other drugs known to prolong the QT interval.
  • Hypersensitivity: Severe allergic reactions, including rash, hives, and swelling of the face, tongue, or throat (angioedema), have been reported.

Common Adverse Reactions

Adverse reactions that occurred frequently (at least 5% and twice the rate of placebo) in clinical trials for Parkinson's disease psychosis include:

  • Peripheral Edema (swelling of hands, ankles, or feet)
  • Confusional State
  • Nausea

Other documented reactions include constipation, hallucination (worsening), and gait disturbance (difficulty walking normally).

Contraindications and Restrictions

This medication is contraindicated in patients with a known history of a hypersensitivity reaction to the drug or its components. Use must be avoided in patients with known QT prolongation, certain heart rhythm disorders, or low potassium or magnesium levels. Concomitant use with strong CYP3A4 inhibitors or inducers requires dosage adjustment or is otherwise restricted due to the potential for significantly altered exposure and increased risk of adverse effects.

Overdose and Emergency Response

Overdose and When to Seek Help

Official regulatory information describes overdose manifestations for Pima (Potassium Iodide) across two classifications: acute poisoning and chronic iodine poisoning (Iodism).

Acute overdose can lead to severe health outcomes, including cardiopulmonary collapse and life-threatening oedema of the glottis (swelling in the throat) that may cause asphyxia or aspiration pneumonia. Acute ingestion may also cause corrosive injury of the gastrointestinal tract and renal damage.

Documented Overdose Manifestations

Classification Manifestations (Examples)
Acute Poisoning Laryngeal edema, Angioedema, Cutaneous hemorrhages
Chronic Poisoning (Iodism) Severe headache, metallic taste, acneform skin lesions, swelling of the salivary glands

Required Emergency Actions

Immediate medical help is required for any suspected overdose. For severe, life-threatening allergic symptoms such as trouble breathing or swelling of the throat, individuals must call 911 or get medical care right away.

Supportive Care: There is no specific antidote documented. Management includes abundant fluid and salt intake to aid iodide elimination and, for severe acute cases, airway maintenance and stabilisation of the circulation.

Special Population Note: Neonates are highly susceptible to thyroid-blocking effects from overdose, requiring close follow-up of thyroid function to prevent potential neurodevelopmental impairment.

Therapeutic Uses of Pima

What Pima Treats: Main Uses and Benefits

Pima (Potassium Iodide) is generally used across distinct clinical areas where supportive symptom management is appropriate or specific preventative action is necessary.

Critical Protection from Radioactive Iodine Exposure

This therapeutic domain addresses a specific preventative necessity in certain nuclear emergency scenarios. Pima is applied to block the absorption of a harmful radioisotope, contributing to the vital therapeutic goal: supporting the reduction of the risk of developing thyroid cancer over time in exposed individuals, particularly children and infants. This supports general well-being during symptomatic phases.

Short-Term Relief for Severe Thyroid Overactivity

Pima is commonly used across conditions characterized by acute symptomatic manifestations, such as Thyroid Storm and severe hyperthyroidism. It helps address symptom clusters that may appear suddenly, offering short-term symptomatic support to support rapid symptom management during periods of severe hormonal distress or pre-surgical preparation.

Managing Viscous Mucus and Respiratory Discomfort

This medication is applied in conditions presenting with systemic or localized discomfort, such as chronic bronchitis, where symptoms may intensify temporarily. It plays a role in managing symptoms like heavy chest congestion and a persistent, dry cough by assisting with thinning and loosening thick, tenacious mucus to ease its expulsion. This contributes to improved comfort and supports functional stability during symptomatic periods.


Quick Fact: Relief for Viscous Mucus

The medication assists patients suffering from chronic pulmonary diseases by softening and thinning phlegm and other thick secretions, which helps improve day-to-day comfort and supports functional stability.

Regulatory References

  1. NIH MedlinePlus Drug Information

Eligibility and Restrictions for Use

The eligibility for Pima (Potassium Iodide) is strictly defined by regulatory documents, distinguishing between groups permitted to use the medicine and those with formal restrictions or contraindications.

Absolute Contraindications

Category Eligibility Rule
Prohibited Use Pima must not be used by individuals with a known allergy or severe sensitivity to iodides. Use is also contraindicated in patients with conditions such as Dermatitis herpetiformis or Hypocomplementemic vasculitis.

Age and Use Restrictions

Population Group Official Regulatory Status
Infants and Children These groups are prioritized for use as a thyroid-blocking agent in radiation emergencies.
Adults over 40 Not recommended for routine thyroid-blocking unless the predicted radiation exposure is deemed extremely high.
Pregnancy/Lactation Permitted, but strictly limited to a single dose to avoid risk of fetal or infant thyroid suppression.
Comorbidity Caution Caution is required in patients with renal insufficiency or certain pre-existing thyroid conditions (e.g., nodular goiter). The safety for its use as an expectorant has not been established in children.

What should I know about interactions with other medicines?

Pima (Potassium Iodide) interaction patterns are governed by its potassium and iodide components, resulting in documented pharmacodynamic effects rather than metabolic enzyme interference. Co-administration with certain medicinal products requires regulatory caution due to the risk of potentiating specific outcomes.

Interactions Increasing Hyperkalemia Risk

The potassium component of Pima can lead to an additive effect when combined with other agents that raise or retain serum potassium levels. Official prescribing information states that concurrent use with Angiotensin-Converting Enzyme (ACE) inhibitors (such as Captopril) or Potassium-sparing Diuretics (such as Triamterene) may enhance the risk of hyperkalemia. This condition is also a population-specific concern, requiring regulatory caution in patients with impaired renal function.

Interactions Increasing Hypothyroid Effects

The iodide component of Pima can reinforce the action of other thyroid-modifying drugs. Co-administration with Lithium or other Antithyroid Drugs is documented to potentiate the hypothyroid and goitrogenic effects of these medications. Similarly, combining Pima with other Iodine-containing Drugs increases the overall body iodine dose, resulting in a documented risk of toxic effects.

Timing-Related Interference

A non-drug interaction constraint noted in regulatory documents is the required timing separation from certain procedures. Pima administration is explicitly documented to interfere with the efficacy of radioiodine therapy and the accuracy of thyroid diagnostic procedures.

Mechanism of Action

Selective Serotonin Receptor Modulation

Pima acts as a selective inverse agonist and antagonist at specific serotonin receptors, primarily 5-HT2A and, to a lesser extent, 5-HT2C receptors. This receptor- or enzyme-mediated signaling initiates a cascade that influences the activity of dysregulated signaling processes within the central nervous system.


Targeted Neurotransmitter System Adjustment

The compound modulates key pathways associated with signaling responses by focusing on the serotonin system. It exhibits minimal to no affinity for dopamine, adrenergic, or muscarinic receptors. This targeted pathway adjustment contributes to the modulation of activity within the serotonin signaling pathways.


Downstream Physiological Modulation

By modifying these early molecular steps at the 5-HT2A receptor, Pima influences the subsequent signaling sequences that lead to systemic physiological consequences. This reduces the magnitude of excessive mediator activity in systems where specific transmitters dominate and modifies the resulting physiological effects associated with overactive signaling.

Dosage and Administration Information

Official Administration Guidelines for Pima

The guidelines for using Pima are established to ensure proper administration. The following details describe the standard structure for the medication's use.


Administration Scope

Guideline Official Instruction
Route of Administration Oral
Official Dosing Rule Take one 50 mg tablet once daily.
Timing in Relation to Meals May be taken with or without food.
Preparation Requirements Tablets must be swallowed whole with water; do not crush, cut, or chew the tablet.
Age-Group Rules Approved for use in adults and pediatric patients aged 12 years and older.
Missed-Dose Rules If a dose is missed, take it as soon as remembered unless it is within 8 hours of the next scheduled dose. If so, skip the missed dose and resume the regular schedule. Do not double the dose.
Special Procedural Conditions None explicitly documented.

Resulting Procedural Structure

Official Step Sequence:

  • Verify the prescribed dose is the 50 mg tablet form of Pima.
  • Take the dose one time daily, preferably at the same time each day.
  • Swallow the tablet whole with liquid.
  • Follow the missed-dose instructions if the daily dose is not taken on schedule.

This structure reflects the patient-use instructions provided for the medication.

Recent Clinical Evidence

Research evidence / Overview of studies

A. Efficacy in Acute Pain Relief

Research has investigated the drug's role in addressing acute pain. One large-scale study assessed the drug's performance by observing changes in pain scores over a short duration of use. Studies evaluated whether the combination of two active ingredients is associated with observed outcomes and compared outcomes to those observed with standard treatments. Clinical trials detailed the experience of adults who participated in the research.

B. Effects on Chronic Inflammation

Studies have evaluated whether drug exposure is associated with the long-term observation of inflammatory markers. Results showed an association between drug exposure and measured inflammatory markers, which is a focus area of pain research. The research reported findings regarding consistent use, with some studies reporting on the relationship between consistent use over a period of at least 12 weeks and the measured results. Specific research sub-groups excluded individuals with severe liver issues.

C. Safety and Tolerability Profile

The tolerability of the drug was evaluated. Clinical trials reported that certain side effects were common, with observations made on their severity and duration. Studies also indicated the frequency of severe adverse events.

Key Studies & References FDA Approved Labeling and Patient Information for Pima Tablets

Frequently Asked Questions (FAQ)

Common questions about Pima (FAQ)

Q: Is Pima a type of antibiotic?

A: Pima, which contains potassium iodide, is not classified as an antibiotic. Official documents describe it as an antithyroid agent and an expectorant. This means its purpose is related to thyroid function or helping to clear mucus, rather than fighting bacterial infections.


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

A: For its use in radiation protection, regulatory guidance indicates that a single dose is often sufficient and provides protection for about 24 hours. For other uses, such as treating thyroid conditions, the duration of use is described as variable and subject to determination by the healthcare team.


Q: Are the side effects of Pima generally considered mild?

A: Official product information lists both common adverse reactions, such as nausea and rash, and serious risks, including thyroid problems and severe allergic reactions. For its radiation protection use, regulatory documents state the drug is approved based on the risk-benefit profile, which includes both common and serious side effects. The full safety profile is important for understanding the use of the drug.


Q: What is the risk of having an allergic reaction to Pima?

A: Regulatory documents state that severe allergic reactions have been reported, although they are noted as rare. Information regarding serious reactions, such as trouble breathing, swelling of the face, or wheezing, is included in the official safety materials.


Q: Can I drive a car while I am taking Pima?

A: Official product information indicates that side effects like confusion and dizziness or lightheadedness are possible, though less frequent. If these effects occur, activities requiring mental alertness, such as driving or operating machinery, may be affected.


Q: Are there different strengths or dosages available for Pima?

A: Yes, Pima (potassium iodide) is available in several forms to provide different administration options. Official drug documents specify that it is available as tablets in strengths such as 65 mg and 130 mg, as well as an oral solution typically dosed as 65 mg per milliliter.


Q: Do studies show Pima helps with the main use it treats?

A: Yes. Regulatory documents confirm that Pima is FDA-approved to be used as a method for blocking thyroid exposure to radioactive iodine. This protection is intended to reduce the risk of developing thyroid cancer later in life following exposure.


Q: Can Pima cause changes in mood?

A: Official product information for Pima lists confusion as a less frequent adverse reaction. This is a change in mental state which is included in the reported profile, though specific changes in emotional mood, like anxiety or depression, are not typically highlighted as common side effects.


Q: Why do official documents state Pima is for a specific population?

A: The specific age and population rules for Pima are based on regulatory guidance designed to minimize risk. For instance, restrictions for adults over 40 are based on the balance of risk and benefit, which changes across age groups due to the increased risk of thyroid problems in certain populations if the drug is taken unnecessarily.


Q: How quickly does Pima start working after taking it?

A: For radiation protection, official guidance indicates that Pima should be taken within a specific time window, such as up to 24 hours before or within a few hours after exposure, as part of the administration procedure. The drug begins to achieve thyroid-blocking protection soon after it is administered.


Q: Can Pima cause fatigue or tiredness?

A: The official product label for potassium iodide lists unusual tiredness as one of the less frequent adverse reactions that have been reported. This observation is part of the reported safety profile.


Q: Are there any specific foods that interact with Pima?

A: Official drug documents indicate there are no known interactions between potassium iodide and specific foods or drinks. For patient comfort, it is noted that the medication may be taken with food to potentially reduce stomach discomfort.


Q: Does Pima require any special monitoring by a doctor?

A: Caution is advised in patients who have pre-existing conditions, particularly those with renal function impairment (kidney issues) or certain pre-existing thyroid conditions. These circumstances require a heightened level of caution, as noted in the official warnings.


Q: Does Pima affect blood pressure?

A: Pima is noted to interact with certain medications used for high blood pressure, such as ACE inhibitors, which can increase the risk of a condition called hyperkalemia (high potassium levels). A direct effect on blood pressure is not typically listed as a common side effect of Pima itself.


Q: Is Pima considered a controlled substance?

A: No. Pima (potassium iodide) is classified by regulatory bodies as not a controlled medication. It does not have a DEA Schedule classification.


Q: Can Pima cause dizziness or lightheadedness?

A: Yes, regulatory information indicates that dizziness or feeling lightheaded are potential symptoms that may occur, particularly if a person is experiencing a severe allergic reaction to Pima.


Q: Are there specific warnings about Pima and alcohol consumption?

A: According to official product information, it is generally unknown if drinking alcohol will affect potassium iodide. Information regarding the combining of Pima with alcohol is best clarified by a healthcare professional.


Q: How is Pima eliminated from the body?

A: Official documents note that the intake of abundant fluids and salt is known to aid in the elimination of iodide from the body. The body’s natural elimination process for iodide is noted to be aided by the intake of abundant fluids and salt.


Q: Is Pima available over the counter in any country?

A: In the United States, Pima (potassium iodide) tablets are typically available over the counter (OTC). However, the oral solution form often requires a prescription.


Q: Is it normal to feel no immediate effect after starting Pima?

A: Yes, this is normal. When taken as a single dose for emergency protection, the risk of adverse reactions is considered remote. Since the drug's effect is internal (blocking the thyroid), feeling no immediate physical change is common.

How should Pima be stored and disposed of?

Storage Requirements

Pima (Potassium Iodide) must be stored at controlled room temperature, specifically between 20 C to 25 C (68 F to 77 F), with permitted excursions up to 30 C (86 F). The product must be kept dry, protected from light, and the foil packet for the tablets must remain intact. It is essential to keep from freezing and to store the medication in its original container with the cap tightly closed.

Stability and Child Safety

To preserve the product's full shelf-life (typically six years), the regulatory storage conditions must be maintained. A liquid mixture prepared from the tablets for administration should be stored in the refrigerator (2 C to 8 C) and must be discarded after 7 days. All medicine must be kept out of the reach of children.

Disposal Instructions

Unused or expired Pima must be disposed of according to local, state, and national regulations. Patients are instructed to dispose of the tablets in regular household trash, often after mixing them with an unappealing substance, but must not flush the tablets down the toilet or pour them into any drain or water supply.

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

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