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ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS

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Doctor

Daniel Cichi

Family medicine 24 years exp.

Dr Daniel Cichi is a family medicine doctor with over 20 years of clinical experience. He provides online consultations for adults, supporting patients with acute symptoms, chronic conditions, and everyday health concerns that require timely medical guidance. His background includes work in emergency care, ambulance services, and family medicine, which allows him to assess symptoms quickly, identify warning signs, and help patients choose the safest next steps – whether that means home care, treatment adjustment, or in-person evaluation. Patients commonly consult Dr Daniel Cichi for: 

  • acute symptoms: fever, infections, flu-like illness, cough, sore throat, shortness of breath;
  • chest discomfort, palpitations, dizziness, fatigue, and blood pressure concerns;
  • digestive problems: abdominal pain, nausea, diarrhoea, constipation, reflux;
  • sexually transmitted infections, erectile dysfunction;
  • muscle, joint, and back pain, minor injuries, post-traumatic symptoms;
  • chronic conditions: hypertension, diabetes, high cholesterol, thyroid disorders, weight loss, hair loss;
  • review and interpretation of lab tests, imaging reports, and medical documents;
  • medication review and treatment adjustment;
  • medical advice while travelling or living abroad;
  • second opinions and guidance on whether in-person care is needed.

Dr Cichi’s consultations are structured and practical. He focuses on clear explanations, risk assessment, and actionable recommendations, helping patients understand their symptoms and make informed decisions about their health.

This page is for general information. Consult a doctor for personal advice. Call emergency services if symptoms are severe.
About the medicine

How to use ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS

Translated with AI

This page provides general information and does not replace a doctor’s consultation. Always consult a doctor before taking any medication. Seek urgent medical care if symptoms are severe.

Show original

Introduction

Package Leaflet: Information for the User

ALKA-SELTZER2.1 gEffervescent Tablets

Sodium Hydrogen Carbonate

Read the package leaflet carefully before starting to use this medicine because it contains important information for you.

Follow the administration instructions of the medicine contained in this package leaflet or as indicated by your doctor or pharmacist.

  • Keep this package leaflet, as you may need to read it again.
  • If you need advice or more information, consult your pharmacist.
  • If you experience side effects, consult your doctor or pharmacist, even if it is a side effect not listed in this package leaflet. See section 4.
  • You should consult a doctor if it worsens or does not improve after 14 days.

Contents of the Package Leaflet:

  1. What is Alka-Seltzer and what is it used for
  2. What you need to know before taking Alka-Seltzer
  3. How to take Alka-Seltzer
  4. Possible side effects
  5. Storage of Alka-Seltzer
  6. Package Contents and Additional Information

1. What is Alka-Seltzer and what is it used for

It belongs to the group of medicines called antacids that work by reducing excess stomach acidity.

This medicine is indicated for the symptomatic relief of heartburn and stomach acid in adults and adolescents from 12 years old.

Doctor consultation

Not sure if this medicine is right for you?

Discuss your symptoms and treatment with a doctor online.

2. What you need to know before taking Alka-Seltzer

Do not take ALKA-SELTZER:

  • If you are allergic to sodium hydrogen carbonate or any of the other components of this medicine (listed in section 6).
  • If you have metabolic or respiratory alkalosis.
  • If you have hypocalcemia
  • If you have hypochlorhydria
  • If you have a tendency to form edema (fluid retention).
  • If you have appendicitis or its symptoms (nausea, vomiting, cramps, abdominal pain).
  • If you have intestinal obstruction (partial or total blockage of the intestine that produces an interruption of the passage of intestinal contents through it).

Warnings and Precautions

Consult your doctor or pharmacist before taking Alka-Seltzer.

As with other antacids, this medicine may mask the symptoms of a more serious stomach disease, so if the symptoms persist or worsen after 14 days of treatment, you should consult your doctor.

It is recommended to use this medicine with caution in patients with hypertension (high blood pressure), in patients with liver, kidney, and heart disease, edema, hypokalemia, hypocalcemia, and aldosteronism (syndrome associated with increased secretion of aldosterone by the adrenal gland) and in patients undergoing diuretic treatment as it may produce hypochloremic alkalosis.

Taking Alka-Seltzer at high doses or for prolonged periods could lead to metabolic alkalosis.

Due to its citric acid content, it is recommended to use with caution in patients with uric acid stones as it may favor the formation of calcium stones.

Children and Adolescents

Do not administer this medicine to children under 12 years old.

Taking Alka-Seltzer with other medicines

Tell your doctor or pharmacist if you are taking, have recently taken, or may take any other medicine.

This is especially important in the case of:

  • ketoconazole (used to treat fungal infections)
  • quinolones, tetracyclines (especially doxycycline), acidic forms of sulfonamide, erythromycin, methenamine (different classes of antibiotics)
  • iron salts (medicines used to prevent or treat anemia)
  • naproxen, salicylates (used to treat pain and fever),
  • valproic acid (used to treat epilepsy)
  • levodopa (used to treat Parkinson's disease)
  • amphetamines, dexamphetamine, ephedrine (central nervous system stimulants)
  • cardiac antiarrhythmics
  • methadone (used to relieve intense pain)
  • meCamylamine (medicine for hypertension)
  • lithium salts (used in some psychiatric illness)
  • barbiturates
  • methotrexate (used to treat cancer and rheumatoid arthritis)
  • preparations containing calcium, as it may develop the milk-alkali syndrome whose symptoms are: excess calcium in the blood, kidney problems, heart problems, metabolic alkalosis, dizziness, vomiting, muscle cramps, apathy, headache, confusion states, and anorexia.

As with other antacids, this medicine administered with enteric-coated medicines may cause the coating to dissolve too quickly, which can produce gastric or duodenal irritation.

Antacids modify the absorption of numerous medicines, so in general, their administration should be spaced out from any other medicine. In general, the intake of this medicine should be done at least 2 hours before or after the administration of any other medicine.

Tell your doctor or pharmacist if you are taking or have recently taken any other medicine, even those purchased without a prescription.

Interference with diagnostic tests:

If you are going to have any diagnostic test (including blood tests, urine tests, detection of gastric acid secretion, etc.), inform your doctor that you are taking this medicine, as it may alter the results.

Taking ALKA-SELTZER with food and drinks:

Do not take this medicine with milk or dairy products.

Due to its sodium hydrogen carbonate content, this medicine should not be taken immediately after excessive food or drink, as it may cause an increase in carbon dioxide production, which could lead to gastric distension and, in rare cases, may perforate the stomach walls.

Pregnancy, Breastfeeding, and Fertility

If you are pregnant or breastfeeding, or think you may be pregnant or plan to become pregnant, consult your doctor or pharmacist before using this medicine.

Driving and Using Machines:

No effect of Alka-Seltzer on the ability to drive and use machines has been described.

Alka-Seltzer contains Sodium and Aspartame (E-951).

This medicine contains 570 mg of sodium (main component of table salt/cooking salt) in each effervescent tablet. This is equivalent to 28.5% of the maximum recommended sodium intake for an adult.

Consult your doctor or pharmacist if you need 6 or more effervescent tablets per day for a prolonged period, especially if you have been recommended a low-salt diet (sodium).

This medicine contains 10 mg of aspartame in each effervescent tablet. Aspartame contains a source of phenylalanine that may be harmful in case of phenylketonuria (PKU), a rare genetic disease in which phenylalanine accumulates because the body is unable to eliminate it properly.

3. How to take Alka-Seltzer

Follow the administration instructions of this medicine contained in this package leaflet or as indicated by your doctor or pharmacist. In case of doubt, ask your doctor or pharmacist.

This medicine is administered orally.

The recommended dose is:

Adults and adolescents from 12 years old: The usual dose is 1 effervescent tablet, if necessary increased to 2, after meals or when feeling gastric discomfort.

Do not exceed 6 tablets per day.

Elderly over 65 years: Do not exceed 3 tablets per day.

Patients with renal insufficiency

They should consult their doctor before taking this medicine.

Use in children and adolescents

Do not use in children under 12 years old.

Always use the lowest effective dose.

If you think the effect of ALKA-SELTZER is too strong or too weak, tell your doctor or pharmacist.

Do not take this medicine with a stomach excessively full of food or drink. You should wait between 20 minutes and 1 hour after meals before taking the medicine. It is necessary to wait until the effervescent tablet has completely dissolved in water and the bubbling has disappeared before taking it. Consult your doctor if you notice a strong stomach pain after taking the medicine.

The administration of this preparation is subject to the appearance of gastric discomfort. As they disappear, this medication should be suspended.

If the symptoms persist for more than 14 days or worsen or other symptoms appear, you should interrupt the treatment and consult your doctor.

If you take more ALKA-SELTZER than you should

The main symptoms of overdose are metabolic alkalosis (headache, dizziness, ringing in the ears, blurred vision, drowsiness, sweating, nausea, vomiting, occasionally diarrhea, hyperirritability, and tetany (muscle weakness)) and fluid retention.

In case of overdose or accidental ingestion, consult your doctor or pharmacist immediately or go to a medical center immediately or call the Toxicology Information Service, phone: 91 562 04 20, indicating the medicine and the amount ingested.

If you forget to take ALKA-SELTZER:

Do not take a double dose to make up for forgotten doses.

Medicine questions

Started taking the medicine and have questions?

Discuss your symptoms and treatment with a doctor online.

4. Possible side effects

Like all medicines, Alka-Seltzer can cause side effects, although not everyone gets them.

Adverse reactions are listed in decreasing order of severity within each frequency interval.

The convention used for the definition of frequencies is as follows: very common (≥1/10); common (≥1/100 to <1>

Frequency not known (frequency cannot be estimated from available data):Flatulence (gas in the stomach or intestine), belching, vomiting, cramps, stomach distension, and rebound effect (increase in acidity produced by the medicine itself).

Hypokalemia (decrease in potassium levels in the blood) and hypernatremia (increase in sodium levels in the blood).

If used continuously or at high doses, it may produce systemic alkalosis, whose symptoms include difficulty breathing, muscle weakness, increased muscle tone, spasms, tetany (involuntary muscle contraction), especially with hypercalcemia, anxiety, and other effects on the central nervous system.

Hypertension (high blood pressure) and edema (fluid retention) if used continuously or at high doses.

With unknown frequency, oral ingestion of Sodium Hydrogen Carbonate has caused spontaneous gastric perforation due to gas production.

Excessive oral administration of medicines containing citrate salts may have a laxative effect.

Reporting of side effects:

If you experience any side effect, consult your doctor or pharmacist, even if it is a possible side effect not listed in this package leaflet. You can also report them directly through the Spanish Medicines and Health Products Agency's website: http://www.notificaram.es. By reporting side effects, you can help provide more information on the safety of this medicine.

5. Storage of Alka-Seltzer

Keep this medicine out of the sight and reach of children.

Keep the container tightly closed.

Do not use Alka-Seltzer after the expiration date stated on the container, after the abbreviation CAD. The expiration date is the last day of the month indicated.

Medicines should not be disposed of via wastewater or household waste. Place the containers and medicines you no longer need in the pharmacy's SIGRE collection point. If in doubt, ask your pharmacist how to dispose of containers and medicines you no longer need. This will help protect the environment.

6. Package Contents and Additional Information

Composition of Alka-Seltzer

  • The active ingredient is Sodium Hydrogen Carbonate. Each effervescent tablet contains 2.1 g (2081.8 mg) of sodium hydrogen carbonate (sodium bicarbonate).
  • The other ingredients (excipients) are citric acid, aspartame (E-951), mannitol (E-421), acesulfame potassium, lemon-lime flavor, vanilla flavor, and amiflex (a compound of amino acids, glutamic acid, and sodium chloride).

Appearance of the product and package contents:

This medicine is effervescent tablets, round and white in color. They are available in containers of 10 or 20 effervescent tablets.

Some container sizes may not be marketed.

Marketing Authorization Holder

BAYER HISPANIA, S.L.

Av. Baix Llobregat, 3-5

08970 Sant Joan Despí (Barcelona)

Manufacturer:

BAYER BITTERFELD GmbH

OT Greppin

Salegaster Chaussee, 1

06803 Bitterfeld-Wolfen

Germany

Date of the last revision of this package leaflet: September 2019

Detailed and updated information on this medicine is available on the website of the Spanish Agency for Medicines and Health Products (AEMPS) http://www.aemps.es/

Online doctors for ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS

Discuss questions about ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS, including use, safety considerations and prescription review, subject to medical assessment and local regulations.

0.0 (17)
Doctor

Daniel Cichi

Family medicine 24 years exp.

Dr Daniel Cichi is a family medicine doctor with over 20 years of clinical experience. He provides online consultations for adults, supporting patients with acute symptoms, chronic conditions, and everyday health concerns that require timely medical guidance. His background includes work in emergency care, ambulance services, and family medicine, which allows him to assess symptoms quickly, identify warning signs, and help patients choose the safest next steps – whether that means home care, treatment adjustment, or in-person evaluation. Patients commonly consult Dr Daniel Cichi for: 

  • acute symptoms: fever, infections, flu-like illness, cough, sore throat, shortness of breath;
  • chest discomfort, palpitations, dizziness, fatigue, and blood pressure concerns;
  • digestive problems: abdominal pain, nausea, diarrhoea, constipation, reflux;
  • sexually transmitted infections, erectile dysfunction;
  • muscle, joint, and back pain, minor injuries, post-traumatic symptoms;
  • chronic conditions: hypertension, diabetes, high cholesterol, thyroid disorders, weight loss, hair loss;
  • review and interpretation of lab tests, imaging reports, and medical documents;
  • medication review and treatment adjustment;
  • medical advice while travelling or living abroad;
  • second opinions and guidance on whether in-person care is needed.

Dr Cichi’s consultations are structured and practical. He focuses on clear explanations, risk assessment, and actionable recommendations, helping patients understand their symptoms and make informed decisions about their health.

5.0 (100)
Doctor

Tarek Agami

General medicine 11 years exp.

Dr. Tarek Agami is a general practitioner registered in both Portugal and Israel, with broad experience in family and preventive medicine. He offers online consultations for adults and children, providing personalised support for primary care needs, chronic disease management, and everyday health concerns.

Dr. Agami received clinical training and worked in leading medical institutions in Israel (Kaplan Medical Center, Barzilai Medical Center, Wolfson Medical Center) and Portugal (European Healthcare City, Viscura Internacional, Hospital Dr. José Maria Grande, Hospital Vila Franca de Xira). His approach combines international medical standards with individualised attention to each patient.

Main areas of consultation:

  • Diagnosis and treatment of acute and chronic conditions (high blood pressure, diabetes, respiratory infections, cardiovascular symptoms)
  • Evaluation of symptoms and guidance on further diagnostic testing
  • Preventive check-ups and regular health monitoring
  • Medical support during travel or after relocation
  • Treatment adjustments and lifestyle recommendations based on your personal history
Dr. Agami provides medical support for patients using GLP-1 medications (such as Ozempic or Mounjaro) as part of a weight loss strategy. He offers individualised treatment planning, regular follow-up, dose adjustment, and advice on combining medication with sustainable lifestyle changes. Consultations follow the medical standards accepted in Portugal and Israel.

Dr. Agami is committed to evidence-based, patient-centred care, ensuring that each person receives trusted medical support tailored to their health goals.

0.0 (0)
Doctor

Andreea Mateescu

Paediatrics 8 years exp.

Dr Andreea Mateescu is a board-certified paediatrician with 7 years of clinical experience. She graduated from Carol Davila University of Medicine and Pharmacy in Bucharest, Romania, and completed her paediatric residency at INSMC Alessandrescu-Rusescu. She also holds additional training in general ultrasound diagnostics.

Dr Mateescu focuses on providing high-quality, evidence-based medical care for children, with a strong emphasis on prevention, healthy development, and long-term wellbeing. She believes that clear, empathetic communication with both children and parents is essential for building trust and ensuring effective care.

Online consultations with Dr Mateescu are suitable for:

  • preventive check-ups and monitoring of growth and development;
  • vaccination planning, including personalised and catch-up schedules;
  • assessment of psychomotor, emotional, and physical development;
  • diagnosis and management of acute and chronic paediatric conditions;
  • nutritional guidance for infants and children, including formula selection when medically indicated;
  • care for children with complex or rare conditions;
  • practical guidance and ongoing support for parents.
Dr Mateescu works with patience, empathy, and professionalism, ensuring that each child receives attentive, individualised care. Her goal is to support healthy, balanced development while helping parents feel confident and well-informed at every stage of their child’s care.
5.0 (85)
Doctor

Lina Travkina

Family medicine 13 years exp.

Dr. Lina Travkina is a licensed family and preventive medicine doctor based in Italy. She provides online consultations for adults and children, supporting patients across all stages of care – from acute symptom management to long-term health monitoring and prevention.

Areas of medical care include:

  • Respiratory conditions: colds, flu, acute and chronic bronchitis, mild to moderate pneumonia, bronchial asthma.
  • ENT and eye conditions: sinusitis, tonsillitis, pharyngitis, otitis, infectious and allergic conjunctivitis.
  • Digestive issues: gastritis, acid reflux (GERD), IBS, dyspepsia, bloating, constipation, diarrhoea, functional bowel symptoms, intestinal infections.
  • Urological and infectious diseases: acute and recurrent cystitis, bladder and kidney infections, prevention of recurrent UTIs, asymptomatic bacteriuria.
  • Chronic conditions: hypertension, diabetes, hypercholesterolemia, metabolic syndrome, thyroid disorders, excess weight.
  • Neurological and general symptoms: headache, migraine, dizziness, fatigue, sleep disturbances, reduced concentration, anxiety, asthenia.
  • Chronic pain support: back, neck, joint, and muscle pain, tension syndromes, pain associated with osteochondrosis and chronic conditions.

Additional care areas:

  • Preventive consultations and check-up planning.
  • Medical advice and follow-up consultations.
  • Test interpretation and diagnostic guidance.
  • Structured support for undiagnosed complaints.
  • Second opinion on diagnoses and treatment plans.
  • Nutritional and lifestyle support for vitamin deficiencies, anaemia, metabolic issues.
  • Post-operative recovery support and pain management.
  • Preconception counselling and postpartum support.
  • Immunity support and strategies to reduce frequency of infections.

Dr. Travkina combines evidence-based medicine with an attentive, personalised approach. Her consultations focus not only on treatment, but also on prevention, recovery, and long-term wellbeing.

If during the consultation it becomes clear that your case requires in-person assessment or specialised care outside of her scope, the session will be terminated and the payment fully refunded.

0.0 (2)
Doctor

Lisa Drigo

Paediatrics 34 years exp.

Dr Lisa Drigo is an experienced paediatrician based in Italy with over 30 years of clinical practice. She graduated from Università Cattolica del Sacro Cuore in Rome and has spent decades working within the Italian healthcare system, supporting children and families with both acute care and long-term prevention.

She is well familiar with Italian paediatric standards, including local vaccination schedules, preventive check-ups, growth monitoring, and everyday medical issues faced by families living in Italy. This makes her consultations especially valuable for parents who want guidance that aligns with local medical practice.

Her primary focus is paediatrics, with additional support in family medicine when a child’s health needs to be assessed in a broader family or preventive context.

Patients most often consult her for:

  • Acute infections in children (fever, cough, sore throat, runny nose).
  • Viral and bacterial illnesses, frequent colds.
  • Digestive symptoms such as abdominal pain, nausea, diarrhoea or constipation.
  • Monitoring of growth, weight, and developmental milestones.
  • Vaccination advice according to Italian schedules.
  • Allergic reactions, skin rashes, food sensitivities.
  • General health concerns and everyday questions from parents.
  • Preventive care, nutrition advice, and healthy lifestyle guidance.

Dr Drigo communicates in a clear, calm, and reassuring way, helping parents understand what is happening and what steps to take next. Online consultations allow families to receive reliable paediatric guidance aligned with Italian medical practice, without unnecessary stress or waiting.

0.0 (11)
Doctor

Lizaveta Trafimchuk Takhvaniuk

Dermatology 10 years exp.

Dr. Lizaveta Trafimchuk Takhvaniuk graduated in Medicine and subsequently specialized in Dermatology and Venereology. She has more than 10 years of clinical experience and is licensed to practice in Spain, where she focuses on the comprehensive diagnosis and treatment of dermatological conditions.

Throughout her education and professional career, Dr. Trafimchuk has gained extensive experience in managing diseases of the skin, hair, and nails, as well as in the diagnosis, treatment, and prevention of sexually transmitted infections (STIs). Her clinical approach is based on evidence-based medicine, combined with personalized care tailored to each patient’s needs.

In her daily practice, she treats a wide range of dermatological conditions, including chronic inflammatory dermatoses such as acne, rosacea, atopic dermatitis, psoriasis, and eczema. She also has experience in treating pigmentation disorders, including melasma, post-inflammatory hyperpigmentation, and dyschromia.

She has developed a particular interest in trichology, treating various types of alopecia, chronic hair loss, and scalp disorders. In addition, she has experience in managing infectious dermatoses of fungal, viral, and bacterial origin, as well as in evaluating benign and suspicious skin lesions, with referral to specialized care when necessary.

With a strong interest in a comprehensive approach to skin health, she also treats scars, post-procedural skin changes, and conditions related to hormonal factors and aging, including those associated with pregnancy, menopause, and age-related skin changes.

Thanks to her experience and continuous professional development, Dr. Trafimchuk provides high-quality medical care that is professional, confidential, and aligned with modern dermatology standards.

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Frequently Asked Questions

Is a prescription required for ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS?

ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS does not require a prescription in Spain. You can check with a doctor online whether this medicine may be appropriate for your situation.

Who manufactures ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS?

ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS is manufactured by Bayer Hispania S.L.. Pharmacy brands and packaging may differ depending on the distributor.

Which doctors can assess the use of ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS online?

Doctors such as Family doctors, Psychiatrists, Dermatologists, Cardiologists, Endocrinologists, Gastroenterologists, Pulmonologists, Nephrologists, Rheumatologists, Hematologists, Infectious disease physicians, Allergists, Geriatricians, Paediatricians, Oncologists may assess whether ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS is appropriate, depending on your situation and local regulations. You can book an online consultation to discuss your symptoms and possible next steps.

How to buy ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS in Spain?

Spain has a well-developed healthcare infrastructure across major cities such as Madrid, Barcelona, Valencia, and Seville. Pharmacies are widely available and operate under strict regulations, ensuring access to prescribed medications.

You can buy ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS in Madrid, Barcelona, Seville, or Valencia at any local pharmacy with a valid prescription.

To obtain a prescription, you can use Oladoctor:

What are the alternatives to ALKA-SELTZER 2.1 g EFFERVESCENT TABLETS?

Other medicines with the same active substance () include BICARBONATE 1 g POWDER FOR ORAL SOLUTION, ACYLINE 620 mg/380 mg/630 mg ORAL SUSPENSION, ALMAGATO STADAPHARM 1.5 G ORAL SUSPENSION. These may have different brand names or formulations but contain the same therapeutic ingredient. Always consult a doctor before switching or starting a new medicine.

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