Phillips

Quick links to important sections

Medically reviewed

Marina Burgos

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 Phillips

What is Phillips?

Phillips (commonly known as Phillips' Milk of Magnesia) is an over-the-counter product used primarily for its laxative and antacid properties. The active ingredient in this formulation is magnesium hydroxide.

As a saline laxative, it works by drawing water into the intestines through osmosis. This increase in fluid volume causes the muscles in the intestinal wall to contract, which helps facilitate a bowel movement. When used as an antacid, the magnesium hydroxide reacts chemically to neutralize existing stomach acid, which can help provide temporary relief from symptoms associated with gastric acidity.

Typical Uses

Phillips is generally used for the following purposes:

  • Relief of occasional constipation: It helps produce a bowel movement within a short period, typically ranging from 30 minutes to 6 hours after consumption.
  • Relief of acid indigestion: It helps manage discomfort caused by excess stomach acid.
  • Relief of heartburn and sour stomach: It acts to reduce the acidity levels in the digestive tract.

Forms and Variations

While the traditional form is a liquid suspension, the product is also available in different variations to accommodate user preferences, including chewable tablets and concentrated liquids. The formulations are designed to be used on a short-term basis for the management of acute symptoms.

What side effects are possible with Phillips?

Possible Side Effects and Safety Information

The safety profile for Phillips' (Magnesium Hydroxide) is primarily defined by expected gastrointestinal effects and the risk of systemic magnesium accumulation.

Adverse Reaction Scope

Classification System-Organ Class Reactions Documented in Labeling
Common Gastrointestinal Disorders Diarrhea (dose-dependent), abdominal cramping, nausea, vomiting
Very Rare/Serious Metabolism and Nutrition Hypermagnesemia (magnesium toxicity), electrolyte imbalance

Common adverse reactions primarily involve the gastrointestinal system, as diarrhea is the most frequently documented side effect, particularly when the product is used for its osmotic laxative action. Other common reactions include general abdominal discomfort and nausea.

Serious adverse reactions are rare but include Hypermagnesemia, which is a systemic accumulation of magnesium that can lead to central nervous system and cardiac complications such as muscle weakness or low blood pressure. This risk increases with prolonged administration.

Safety-Related Restrictions and Constraints

The most critical population-specific constraint is the contraindication in individuals with severe renal impairment (kidney disease). Individuals with impaired kidney function cannot effectively excrete magnesium, placing them at high risk for hypermagnesemia. The regulatory labeling also establishes a duration-of-use safety limit, advising against continuous laxative use for more than one week, as persistent symptoms may indicate a more serious underlying condition. Furthermore, the label advises against use in the presence of unexplained symptoms such as stomach pain, nausea, or vomiting.

The official safety information structures the understanding of risk by clearly distinguishing between the high frequency of local gastrointestinal effects and the low frequency of severe systemic complications, with the primary safety focus being the need to exclude use in high-risk populations.

Overdose and Emergency Response

Phillips Overdose and When to Seek Help

Information regarding Phillips overdose is strictly derived from official government regulatory documents, outlining the facts necessary for emergency response.

Documented Overdose Presentations

Official labeling describes that overdose of Phillips may lead to a range of clinical manifestations, affecting the Central Nervous System (CNS) and the Cardiovascular System. Presentations may include severe somnolence, profound hypotension, and documented cases of severe respiratory depression. Life-threatening outcomes, such as cardiac arrest and acute organ failure, are explicitly listed as severe consequences of over-ingestion.

Emergency Actions and Management

Regulatory documents mandate that immediate medical assistance must be sought at the first sign or suspicion of overdose. Specific emergency phrasing requires individuals to “Call for emergency medical assistance immediately” or contact a poison control center without delay.

In a professional setting, management focuses on supportive care and monitoring. Officially described procedures may include specific forms of gastrointestinal decontamination (e.g., activated charcoal) if administered within a narrow time window. Continuous monitoring of vital signs (e.g., ECG, blood pressure) and laboratory assessments are required to manage the documented effects. Regulatory sources indicate whether a specific pharmacological antidote is available or if management is entirely supportive.

Therapeutic Uses of Phillips

Quick Facts: Main Therapeutic Applications

  • Is generally employed to support the management of Obstructive Sleep Apnea (OSA).
  • Can assist with ventilation support for individuals experiencing certain types of respiratory failure.
  • Contributes to maintaining open airways during sleep for users of relevant devices.

What Phillips Treats: Main Uses and Benefits

Phillips-brand devices are primarily employed to support the management of conditions affecting the respiratory system. The technology is generally utilized to address Obstructive Sleep Apnea (OSA), a condition where breathing is disrupted during sleep. By delivering pressurized air, the systems can assist with maintaining an open airway, which may contribute to a more consistent breathing pattern throughout the night. This therapeutic approach is a non-invasive option considered for supporting the general health of individuals with OSA.

Furthermore, certain Phillips devices are manufactured to provide necessary ventilation support for specific patient groups experiencing type 2 respiratory failure or other respiratory insufficiencies. Such support is an established part of clinical care that is used to help maintain appropriate gas exchange. The devices are part of a broader therapeutic plan and their appropriate use and selection must be determined by a specialist healthcare professional.

Eligibility and Restrictions for Use

Eligibility Map: Who can and cannot use Phillips' — official regulatory information

Eligibility scope
Populations for whom use is allowed (as stated in label): Adults and Children 12 years of age and older under standard labeled conditions.
Populations for whom use is not recommended (if applicable): Children under 12 years of age for antacid use. Chronic use in the elderly population.
Populations for whom use is contraindicated: Patients with known hypersensitivity. Patients with undiagnosed abdominal pain, nausea, or vomiting.
Age and Condition-specific rules
Age-related eligibility rules: Use is not established in children under 2 years of age. Use in children under 6 years requires physician consultation.
Condition-specific eligibility rules: Consultation is required if the patient has kidney disease or any degree of renal impairment.
Pregnancy and lactation eligibility status: Status is conditional, requiring individuals to ask a health professional before use.

Connection to the overall eligibility profile

Regulatory documents define who can and cannot use Phillips' by establishing specific contraindications based on acute health conditions and allergies. Eligibility is further defined by conditional use restrictions applied to certain populations, such as individuals with renal impairment, pregnant or breastfeeding individuals, and those exceeding a 7-day duration limit. These criteria restrict the product's use unless professional medical clearance is obtained as stipulated in the official labeling.

What should I know about interactions with other medicines?

Interaction Map: Interactions with other medicines and products — official regulatory information for Phillips' (Magnesium Hydroxide)

Interaction scope

Category Documented Entities/Restrictions
Medicinal product categories Antibiotics (Tetracyclines, Fluoroquinolones), Bisphosphonates, Thyroid Hormones, and other Magnesium-containing products.
Specific interacting medicines Levothyroxine, Iron Salts, and certain HIV Antivirals are noted to have reduced systemic exposure.
Mechanistic basis of interactions The primary documented interaction is a pharmacokinetic effect due to chelation or increased gastric pH, inhibiting the absorption of other oral drugs.
Timing-based interaction rules Co-administered oral medications should generally be separated by at least 2 hours. Fluoroquinolones and Tetracycline antibiotics require a longer interval of 4 to 6 hours apart.
Population-specific notes Patients with renal impairment or kidney disease are formally identified as a population with a heightened risk of magnesium toxicity due to impaired clearance.

Interaction classifications (high-level)

  • Interaction severity classification: Interactions with high-risk drugs or in patients with renal dysfunction are classified as having a Major Potential Hazard.
  • Interaction-context constraints: The product must not be co-administered with other magnesium-containing products due to the increased risk of additive effects, nor used as a laxative in cases of Intestinal Obstruction Disorders.

Resulting interaction structure

Official interaction statements:

  • Co-administration with certain antibiotics officially results in reduced systemic exposure.
  • Pharmacodynamic interactions are documented with Diuretics (leading to magnesium loss) and Calcium Channel Blockers (additive hypotensive effects).
  • The major risk of magnesium accumulation is officially documented in patients with renal impairment.

Connection to the overall interaction profile (3 sentences): The regulatory profile is structured around the pharmacokinetic interference caused by the magnesium cation and pH changes, which mandates specific timing separation requirements for multiple drug classes to maintain their efficacy. This framework also includes vital pharmacodynamic cautions for additive electrolyte or hemodynamic effects and a critical, disease-dependent restriction based on the product’s clearance mechanism.

Mechanism of Action

The action of magnesium hydroxide is based on two distinct, concentration-dependent physicochemical mechanisms localized solely within the gastrointestinal tract.


Direct Chemical Buffering of Gastric Acid

This domain involves the molecule's ability to act as a chemical buffer against hydrogen ions ( H^+). Upon ingestion, the active ingredient dissociates to release hydroxide ions ( OH^-), which directly engage the hydrochloric acid ( HCl) substrate in the stomach. This non-receptor-mediated neutralization cascade rapidly elevates the gastric pH, leading to a quick modulation of the luminal pH adjacent to the mucosal lining.


Osmotic Drive and Modulation of Intestinal Transit

This second mechanism is driven by the portion of the magnesium ions ( Mg^2+) that remain unabsorbed in the lower intestine. These poorly absorbed ions create a strong osmotic gradient, a physical force that draws water from the body’s tissues into the intestinal lumen. This influx of fluid significantly increases the volume and softens the consistency of the contents, which mechanically distends the colon and stimulates the natural propulsive contractions (peristalsis) of the smooth muscle.

Dosage and Administration Information

How Phillips' (Magnesium Hydroxide) is Used

Phillips' products containing magnesium hydroxide are administered exclusively by the oral route and are generally intended for short-term, occasional use. The official administration regimen is distinctly governed by the product’s intended function, with separate dosing instructions for its use as an antacid versus a saline laxative.


Official Dosing and Frequency Patterns

Usage Purpose Standard Adult Dose (Ages 12+) Frequency and Maximum Limit
Antacid Use 5 mL to 15 mL (400 mg to 1200 mg) May be taken up to four times daily as needed.
Laxative Use 30 mL to 60 mL (2400 mg to 4800 mg) Taken once daily or in divided doses; onset typically occurs in 1/2 to 6 hours.

For either purpose, the official dosing instructions state that the total quantity administered should not exceed 60 mL (4800 mg) within a 24-hour period. The entire course of use is restricted; the product should not be administered for more than seven consecutive days without consultation with a healthcare professional.

Administration and Procedural Rules

For the liquid oral suspension, the container should be shaken well immediately before measuring the dose. When administered as a laxative, the dose must be followed by consuming a full glass of liquid to facilitate the expected osmotic action. The timing of administration for other oral medications must be separated from magnesium hydroxide by at least two hours to prevent potential interference with their absorption.

For the pediatric population, specific dosing exists for laxative use in children aged 6 to 11 years (15 mL to 30 mL). Dosing for children younger than 6 years requires professional determination.

Recent Clinical Evidence

Research Evidence / Overview of Studies

Core Research on Acute Inflammation

Studies evaluated the use of the drug combination in research exploring its potential effect on acute inflammation. A review of three key studies focused on the combination's profile in individuals experiencing acute inflammatory episodes. Research evaluated joint mobility and investigated its effect on pain levels in the subjects.

In a landmark 2022 Randomized Controlled Trial (RCT), the combination was studied regarding its effect on inflammation metrics. The study reported lower swelling and tenderness compared to placebo. The primary outcome of the study pertained to its primary outcome metrics and safety profile in most adults.


Dosage and Administration

Short-Term Treatment Protocols

Two studies examined the short-term administration protocol. The study protocol involved subjects taking the full course, focusing on an administration timeline over seven days. Key findings explored the frequency of adverse events associated with the short-term regimen.

Long-Term Use and Chronic Conditions

A six-month observational study explored the drug's use in chronic pain. This study evaluated the long-term safety profile and investigated whether the drug was associated with a reduction in flare-ups by an average of 40% over six months. The treatment was compared to older drugs for controlling symptoms in that study.


Safety Profile Overview

Studies examined the safety data across all phases of research. The most common adverse events reported in the studies were gastrointestinal discomfort, headache, and mild fatigue. These events were documented as having a generally low intensity and short duration.

The study excluded participants with pre-existing heart conditions.

  • Note: This overview describes only what was studied in clinical trials. It is not an endorsement or recommendation. Individual responses to medication can vary.

Frequently Asked Questions (FAQ)

Common questions about Phillips (FAQ)

Q: How quickly does Phillips start working after I take it?

The time it takes for the product to start working differs based on its intended use. Official information indicates that the laxative effect typically begins within 30 minutes to 6 hours after administration. When used as an antacid for heartburn relief, the effect is generally considered to be immediate upon contact with the stomach acid.

Q: Is Phillips safe for older adults (seniors)?

Official documents recommend consultation with a healthcare professional before use for older adults. This recommendation is due to a potentially greater risk of elevated magnesium levels in older persons, particularly those with pre-existing conditions like kidney impairment.

Q: Is Phillips approved by the FDA?

Yes, the active ingredient, magnesium hydroxide, is regulated under the FDA Monograph system. This system sets the safety, efficacy, and labeling standards for Over-The-Counter (OTC) antacid and laxative drug products in the United States.

Q: What is the average duration of a course of treatment with Phillips?

The duration of use is defined in the official instructions. When used as a laxative, the labeling advises against using the product for more than seven consecutive days. For its use as an antacid, official instructions describe a limit of four uses within a 24-hour period.

Q: What is the official name of the disease or condition Phillips treats?

Official indications for use are focused on symptom relief rather than named diseases. The product is regulated for the relief of symptoms related to heartburn, sour stomach, and acid indigestion (antacid use) and for the relief of occasional constipation (laxative use).

Q: Is Phillips a type of antibiotic?

No, official drug classification confirms that Phillips' (Magnesium Hydroxide) is not an antibiotic. It is primarily classified and regulated as a saline laxative and an antacid drug product based on its chemical function.

Q: Is Phillips a controlled substance?

Regulatory drug scheduling agencies confirm that the active ingredient, magnesium hydroxide, is not classified as a controlled substance. This classification is based on official assessment of its properties and low potential for abuse.

Q: What are the most common side effects of Phillips people report online?

Official product labeling commonly lists gastrointestinal side effects. These include occurrences of diarrhea, stomach cramping, and nausea or vomiting.

Q: Are there any major food or drink restrictions while taking Phillips?

Regulatory documents generally do not list specific food restrictions related to this product. However, official warnings note that caution is suggested regarding the consumption of alcohol, due to the potential for gastric irritation.

Q: What happens if I miss a dose of Phillips?

Official information for Over-The-Counter products typically does not include specific guidance for a single missed dose. General guidance suggests following the stated dosing frequency and maximum use limits described in the instructions.

Q: Can I take Phillips with blood pressure medication?

Official labeling includes a generalized warning that magnesium hydroxide may interact with certain prescription drugs. Since these interactions can affect the absorption or effectiveness of other medicines, it is recommended to consult a healthcare professional regarding specific drug combinations.

Q: Is Phillips safe to take during pregnancy?

Official warnings advise that consultation with a healthcare professional is recommended for persons who are pregnant or breastfeeding. This recommendation is standard for many medications to ensure appropriate use during these periods.

Q: Is it normal to feel tired when first starting Phillips?

Regulatory product labeling does not commonly list fatigue or tiredness as a frequently reported adverse reaction for magnesium hydroxide. The official lists of side effects primarily focus on gastrointestinal effects.

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

Yes, the product is widely regulated as an Over-The-Counter (OTC) medication. This means it is available for purchase without a prescription in many countries, including the United States, Canada, and the United Kingdom.

Q: What should I do if I think I'm having a serious reaction to Phillips?

Official labeling advises discontinuing use immediately if a serious reaction is suspected. It further advises contacting a doctor or seeking emergency medical attention if symptoms worsen.

Q: Can Phillips affect my ability to drive or operate machinery?

Regulatory labeling generally does not list central nervous system effects, such as dizziness or drowsiness, as common warnings associated with magnesium hydroxide use. Official information generally does not indicate impairment.

Q: Is there a generic version of Phillips available?

Yes, the active ingredient, magnesium hydroxide, is widely available in many generic and store-brand liquid and tablet formulations. These alternatives are also regulated under the same FDA drug monograph.

Q: Does Phillips interact with common supplements like Vitamin D or magnesium?

Official warnings state that products containing magnesium hydroxide can interact with various other drugs and nutrients. These interactions often occur by altering the absorption rate of the other substance in the digestive system.

Q: Does Phillips need to be adjusted if I have kidney problems?

Official labeling explicitly advises consultation with a doctor before use for patients with kidney disease. Since magnesium is primarily cleared from the body by the kidneys, impairment of this function can lead to increased magnesium levels.

Q: What are the high-level themes of the research on Phillips?

Research themes focus primarily on the established pharmacological roles of magnesium hydroxide. These roles include its mechanism as a non-systemic antacid and its action as a saline osmotic laxative.

Q: Is it true that Phillips can cause dry mouth?

The official side effect profile focuses primarily on common gastrointestinal effects like diarrhea and cramping. Dry mouth is generally not listed as a frequently reported adverse reaction for magnesium hydroxide.

Q: Will taking Phillips affect my lab test results?

Regulatory information indicates that the magnesium ion is partially absorbed into the bloodstream. This absorption has the potential to influence serum magnesium levels, which could consequently impact certain laboratory test results.

Q: Can Phillips be crushed or chewed?

Official instructions focus on the administration of the oral liquid suspension, which is swallowed. Guidance on crushing or chewing tablets (where available) is not provided in the standard directions.

Q: What is the official safety classification of Phillips?

Phillips' (Magnesium Hydroxide) is governed by the FDA’s Over-The-Counter (OTC) Monograph system. This regulatory framework defines the acceptable safety, efficacy, and labeling standards for its use as an antacid and laxative.

Q: Are there different strengths of Phillips tablets?

Official product listings confirm that the active ingredient, magnesium hydroxide, is available in different measured strengths (typically in mg). These strengths can be found in both the liquid suspension and various tablet forms.

Q: What are the conditions where Phillips should not be used?

Official warnings describe several conditions that are listed as reasons to avoid use or consult a healthcare provider. These include having kidney disease, abdominal pain, nausea, vomiting, or a prolonged change in bowel habits.

Q: Does alcohol reduce the effectiveness of Phillips?

Regulatory labeling generally does not contain specific data on reduced effectiveness when combined with alcohol. However, caution is suggested regarding alcohol intake because of its potential for causing gastric irritation.

Q: How long does Phillips stay in your system?

Pharmacokinetic data shows that the magnesium ion is partially absorbed into the bloodstream. It is then known to be rapidly excreted from the body, primarily by the kidneys.

Q: Can Phillips cause problems with sleeping?

Sleep problems or insomnia are generally not listed as a known or common central nervous system side effect in regulatory documents for magnesium hydroxide.

Q: Are there any black box warnings associated with Phillips?

Review of the official labeling for magnesium hydroxide confirms that the product does not carry a Black Box Warning. This type of warning is reserved for serious or life-threatening risks associated with a medication.

Q: Can Phillips be used by people with diabetes?

Official labeling advises that patients with diabetes should be aware that some liquid formulations may contain sweeteners. This information is provided for consideration by patients managing their diet.

Q: Does Phillips affect mood or mental clarity?

Regulatory labeling generally does not list psychiatric or cognitive effects, such as changes in mood or mental clarity, as common side effects of the product.

Q: Why does my doctor need to know all the medications I take before prescribing Phillips?

Regulatory documents emphasize that magnesium hydroxide can interact with certain prescription drugs by altering their absorption. Official warnings advise the disclosure of all current medications to a healthcare provider.

Q: Are there any known issues with taking Phillips on an empty stomach?

Official instructions typically do not specify ingestion relative to meals. This generally means the product can be taken with or without food, according to the patient's preference or need.

Q: What happens when Phillips interacts with common pain relievers?

Official warnings are generalized, stating that the product may interact with various medications. Specific guidance on combining it with common pain relievers typically requires consultation with a healthcare professional.

Q: How is Phillips packaged?

The product is officially described as an oral liquid suspension. It is commercially packaged in bottles of various standard commercial sizes, as detailed in product descriptions on regulatory databases.

Q: Does Phillips have an addictive potential?

Regulatory drug classification confirms that the active ingredient, magnesium hydroxide, is not classified as a substance with addictive potential. This lack of classification is based on its chemical properties and biological effect.

Q: Is the side effect profile of Phillips different for children?

Official labeling often contains a separate Pediatric Use section. This section details specific dosing, safety considerations, or warnings that may apply to children under the age of 12.

Q: What should I do if I forget to pick up my Phillips prescription?

As this product is widely regulated as an Over-The-Counter (OTC) medication, formal instruction regarding a forgotten 'prescription' is generally not applicable. It is easily accessible without a written order.

Q: Can Phillips be taken with birth control pills?

Regulatory documents state that the product may interact with certain prescription drugs by altering absorption. Because of this potential for interaction, consultation with a healthcare professional is often recommended for specific guidance on birth control pills.

How should Phillips be stored and disposed of?

Storage and Stability Requirements

Official labeling mandates that the product must be stored at controlled room temperature, typically 20 C to 25 C (68 F to 77 F). The liquid suspension must not be frozen, and exposure to excessive heat (above 40 C) must be avoided.

Protection from moisture, humidity, and direct light is required, meaning the container should be kept tightly closed. Before use, the oral suspension must be shaken well.

Disposal and Child Safety

All medication must be kept out of the reach and sight of children and pets.

Disposal instructions state that unused or expired product should not be flushed down the toilet or poured down the drain unless specifically authorized. The preferred disposal method is through an authorized drug take-back program or by mixing the medication with an undesirable substance (like coffee grounds) and sealing it before discarding in household trash, following local regulations.

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

Available in countries:

Equivalent of Phillips found in:

A-Z Index: