Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Zantac (Ranitidine). If you are concerned about side effects, discuss the risks and benefits of Zantac (Ranitidine) with your doctor.

The following side effects have been reported by at least 1% of people taking Zantac (Ranitidine). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• changed sense of taste
• Constipation
• Diarrhea
• dizziness
• drowsiness
• Dry Mouth
• headache
• muscle or joint pain
• nausea
• trouble sleeping
• vomiting
• weakness

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• blurred vision
• breast development (males)
• change of heartbeat (faster, slower, or irregular)
• confusion
• decreased sexual ability
• hair loss
• hallucination (hearing or seeing things that aren't there)
• increased frequency of infections
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of Depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• skin rash or Hives
• stomach pain

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, Fever, chills, rapid heartbeat, swollen abdomen)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Zantac (Ranitidine).

Injection
Each mL of solution for IV or IM injection contains 28 mg of Zantac (Ranitidine) HCl (equivalent to 25 mg of Zantac (Ranitidine) anhydrous free base) in sterile water for injection. Nonmedicinal ingredients: disodium hydrogen orthophosphate, phenol (5 mg/mL), and potassium dihydrogen orthophosphate.

Tablets

150 mg
Each white, round, biconvex, film-coated tablet engraved "ZANTAC 150" on one side and "GLAXO" on the other contains 168 mg of Zantac (Ranitidine) HCl (equivalent to 150 mg of Zantac (Ranitidine) anhydrous free base). Nonmedicinal ingredients: magnesium stearate and microcrystalline cellulose; film-coating suspension: hydroxypropyl methylcellulose, titanium dioxide, and triacetin. Gluten- and tartrazine-free.

300 mg
Each white, capsule-shaped, film-coated tablet engraved "ZANTAC 300" on one side and "GLAXO" on the other contains 336 mg of Zantac (Ranitidine) HCl (equivalent to 300 mg of Zantac (Ranitidine) anhydrous free base). Nonmedicinal ingredients: croscarmellose sodium, magnesium stearate, and microcrystalline cellulose; film-coating suspension: hydroxypropyl methylcellulose, titanium dioxide, and triacetin. Gluten- and tartrazine-free.

Do not take Zantac (Ranitidine) if you:

• are allergic to Zantac (Ranitidine) or any ingredients of the medication
• are allergic to any other H2-antagonist (e.g., Cimetidine, Famotidine)

There may be an interaction between Zantac (Ranitidine) and any of the following:

• Amiodarone
• antacids (e.g., magnesium hydroxide, calcium carbonate; within 2 hours of taking Zantac (Ranitidine))
• "azole" antifungals (e.g., itraconazole, ketoconazole, posaconazole)
• cefuroxime
• clavulanic acid
• Cyclosporine
• delavirdine
• dexmethylphenidate
• Diltiazem
• Dronedarone
• Fluvastatin
• Glyburide
• HIV protease inhibitors (e.g., darunavir, indinavir, lopinavir, saquinavir, tipranavir)
• iron salts (e.g., ferrous fumarate, ferrous gluconate, ferrous sulfate)
• ledipasvir
• lumacaftor
• Mesalamine
• Metformin
• Methylphenidate
• midazolam
• Pentoxifylline
• Prasugrel
• procainamide
• protein kinase inhibitors (e.g., Bosutinib, Dabrafenib, Dasatinib, Nilotinib, Pazopanib)
• quinidine
• quinine
• rilpivirine
• Risedronate
• St. John's wort
• Sucralfate
• Tacrolimus
• Varenicline
• velpatasvir
• Verapamil
• Warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Zantac (Ranitidine). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Zantac (Ranitidine).

Kidney function: Kidney Disease or reduced kidney function may cause Zantac (Ranitidine) to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how Zantac (Ranitidine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Zantac (Ranitidine), and whether any special monitoring is needed.

Pneumonia: People with lung disease, a weak immune system, or Diabetes may be at an increased risk of developing pneumonia while taking Zantac (Ranitidine). If you have any of these conditions, discuss with your doctor how Zantac (Ranitidine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Zantac (Ranitidine), and whether any special monitoring is needed.

Porphyria: Zantac (Ranitidine) may cause attacks of a condition called acute porphyria (a disorder that affects the production of heme in the body). People with a history of acute porphyria should not take Zantac (Ranitidine).

Stomach cancer: Using medications such as Zantac (Ranitidine) may prevent symptoms of stomach cancer from being noticed. If you have recurrent vomiting, difficulty swallowing, blood in the stool, significant unintentional weight loss, fatigue (Anemia), or are coughing up blood, check with your doctor right away. If you have heartburn that worsens or returns after using Zantac (Ranitidine) continuously for 2 weeks, check with your doctor.

Use with NSAIDs: If you are also taking non-steroidal anti-inflammatory drugs (NSAIDs; e.g., Diclofenac, Ibuprofen, Naproxen), your doctor should closely monitor your condition, especially if you are a senior or have a history of ulcers.

Pregnancy: Zantac (Ranitidine) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Zantac (Ranitidine), contact your doctor immediately.

Breast-feeding: Zantac (Ranitidine) passes into breast milk. If you are a breast-feeding mother and are taking Zantac (Ranitidine), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Zantac (Ranitidine) have not been established for children less than 8 years of age. Children between the ages of 8 years and 16 years of age, should only use Zantac (Ranitidine) under the supervision of a doctor.

Seniors: Seniors may be more likely to experience interactions with other medications when taking Zantac (Ranitidine). If you are a senior, your doctor should closely monitor your condition.