Medical

Doctors
Hospitals
Terminology

Home

Drugs (Penicillin)*

Description

Penicillins are used in the treatment of bacterial infections. They work by killing bacteria or preventing their growth.

There are several different kinds of penicillins. Each is used to treat different kinds of bacterial infections. One kind of penicillin usually may not be used in place of another.

Penicillins are used to treat bacterial infections in many different parts of the body. They are sometimes given with other antibacterial medicines. Carbenicillin taken by mouth is used only to treat bacterial infections of the urinary tract and prostate gland. Penicillin G and penicillin V are also used to prevent "strep" infections in patients with a history of rheumatic heart disease. Piperacillin is given by injection to prevent bacterial infections before, during, and after surgery also. Some of the penicillins may also be used for other problems as determined by your doctor. However, none of the penicillins will work for colds, flu, or other virus infections.

Penicillins are available only with your doctor's prescription, in the following dosage forms:

Oral
Amoxicillin
• Capsules (U.S. and Canada)
• Oral suspension (U.S. and Canada)
• Chewable tablets (U.S. and Canada)
Amoxicillin and Clavulanate
• Oral suspension (U.S. and Canada)
• Tablets (U.S. and Canada)
• Chewable tablets (U.S.)
Ampicillin
• Capsules (U.S. and Canada)
• Oral suspension (U.S. and Canada)
Bacampicillin
• Oral suspension (U.S.)
• Tablets (U.S. and Canada)
Carbenicillin
• Tablets (U.S. and Canada)
Cloxacillin
• Capsules (U.S. and Canada)
• Oral solution (U.S. and Canada)
Cyclacillin
• Tablets (U.S.)
Dicloxacillin
• Capsules (U.S.)
• Oral suspension (U.S.)
Nafcillin
• Capsules (U.S.)
• Oral solution (U.S.)
• Tablets (U.S.)
Oxacillin
• Capsules (U.S.)
• Oral solution (U.S.)
Penicillin G Benzathine
• Oral suspension (Canada)
Penicillin G Potassium
• Oral solution (U.S.)
• Tablets (U.S. and Canada)
Penicillin V Benzathine
• Oral suspension (Canada)
Penicillin V Potassium
• Oral solution (U.S. and Canada)
• Tablets (U.S. and Canada)

Parenteral
Ampicillin
• Injection (U.S. and Canada)
Ampicillin and Sulbactam
• Injection (U.S.)
Azlocillin
• Injection (U.S.)
Carbenicillin
• Injection (U.S. and Canada)
Cloxacillin
• Injection (Canada)
Methicillin
• Injection (U.S.)
Mezlocillin
• Injection (U.S.)
Nafcillin
• Injection (U.S. and Canada)
Oxacillin
• Injection (U.S.)
Penicillin G Benzathine
• Injection (U.S. and Canada)
Penicillin G Potassium
• Injection (U.S. and Canada)
Penicillin G Procaine
• Injection (U.S. and Canada)
Penicillin G Sodium
• Injection (U.S. and Canada)
Piperacillin
• Injection (U.S. and Canada)
Ticarcillin
• Injection (U.S. and Canada)
Ticarcillin and Clavulanate
• Injection (U.S. and Canada)

It is very important that you read and understand the following information. If any of it causes you special concern, check with your doctor. Also, if you have any questions or if you want more information about this medicine or your medical problem, ask your doctor, nurse, or pharmacist.

Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For penicillins, the following should be considered:

Allergies -- Tell your doctor if you have ever had any unusual or allergic reaction to any of the penicillins, cephalosporins, griseofulvin (e.g., Fulvicin), or penicillamine (e.g., Cuprimine). Also tell your doctor and pharmacist if you are allergic to any other substances, such as foods, preservatives, or dyes, or procaine (e.g., Novocain) or other ester-type anesthetics (medicines that cause numbing) if you are receiving penicillin G procaine.

Pregnancy -- Studies have not been done in pregnant women. However, penicillins have not been shown to cause birth defects or other problems in animals given more than 25 times the usual human dose.

Breast-feeding -- Most penicillins pass into the breast milk. Even though only small amounts may pass into breast milk, allergic reactions, diarrhea, fungus infections, and skin rash may occur in nursing babies.

Age Groups

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For penicillins, the following should be considered:

Children -- Many penicillins have been used in children and, in effective doses, are not expected to cause different side effects or problems in children than they do in adults.

Older adults -- Penicillins have been used in the elderly and have not been shown to cause different side effects or problems in older people than they do in younger adults.

Other Therapy

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For penicillins, the following should be considered:

Other medicines -- Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking a penicillin, it is especially important that your doctor and pharmacist know if you are taking any of the following:

• Amiloride (e.g., Midamor) or
• Captopril (e.g., Capoten) or
• Enalapril (e.g., Vasotec) or
• Lisinopril (e.g., Prinivil, Zestril) or
• Potassium-containing medicine or
• Spironolactone (e.g., Aldactone) or
• Triamterene (e.g., Dyrenium) -- Use of these medicines with penicillin G by injection may cause an increase in side effects

• Anticoagulants (blood thinners) or
• Dipyridamole (e.g., Persantine) or
• Divalproex (e.g., Depakote) or
• Heparin (e.g., Panheprin) or
• Inflammation or pain medicine (except narcotics) or
• Moxalactam (e.g., Moxam) or
• Pentoxifylline (e.g., Trental) or
• Plicamycin (e.g., Mithracin) or
• Sulfinpyrazone (e.g., Anturane) or
• Valproic acid (e.g., Depakene) -- Use of these medicines with carbenicillin or ticarcillin may increase the chance of bleeding

• Cholestyramine (e.g., Questran) or
• Colestipol (e.g., Colestid) -- Use of these medicines with oral penicillin G may prevent penicillin G from working properly

• Oral contraceptives (birth control pills) containing estrogen -- Use of ampicillin, bacampicillin, or penicillin V with estrogen-containing oral contraceptives may prevent oral contraceptives from working properly, increasing the chance of pregnancy

• Probenecid (e.g., Benemid) -- Probenecid increases the blood level of many penicillins. Although your doctor may give you probenecid with a penicillin to treat some infections, in other cases, this effect may be unwanted and may increase the chance of side effects

Other medical problems -- The presence of other medical problems may affect the use of penicillins. Make sure you tell your doctor if you have any other medical problems, especially:

• Allergy, general (such as asthma, eczema, hay fever, hives), history of -- Patients with a history of general allergies may be more likely to have a severe reaction to penicillins if an allergy develops

• Bleeding problems, history of -- Patients with a history of bleeding problems may have an increased chance of bleeding when receiving carbenicillin or ticarcillin

• Kidney disease -- Patients with kidney disease may have an increased chance of side effects

• Mononucleosis, infectious ("mono") -- Patients with infectious mononucleosis may have an increased chance of skin rash

• Stomach or intestinal disease, history of (especially colitis, including colitis caused by antibiotics, or enteritis) -- Patients with a history of stomach or intestinal disease may be more likely to develop colitis while taking penicillins

Before you begin using any new medicine (prescription or nonprescription) or if you develop any new medical problem while you are using this medicine, check with your doctor, nurse, or pharmacist.

Proper Use of This Medicine

Penicillins (except bacampicillin tablets, amoxicillin, amoxicillin and clavulanate combination, and penicillin V) are best taken with a full glass (8 ounces) of water on an empty stomach (either 1 hour before or 2 hours after meals) unless otherwise directed by your doctor.

For patients taking amoxicillin, amoxicillin and clavulanate combination, and penicillin V:

• Amoxicillin, amoxicillin and clavulanate combination, and penicillin V may be taken on a full or empty stomach.

• The liquid form of amoxicillin may also be taken straight or mixed with formulas, milk, fruit juice, water, ginger ale, or other cold drinks. If mixed with other liquids, take immediately after mixing. Be sure to drink all the liquid to get the full dose of medicine.

For patients taking bacampicillin:

• The liquid form of this medicine is best taken with a full glass (8 ounces) of water on an empty stomach (either 1 hour before or 2 hours after meals) unless otherwise directed by your doctor.

• The tablet form of this medicine may be taken on a full or empty stomach.

For patients taking penicillin G by mouth:

• Do not drink acidic fruit juices (for example, orange or grapefruit juice) or other acidic beverages within 1 hour of taking penicillin G since this may keep the medicine from working properly.

For patients taking the oral liquid form of penicillins:

• This medicine is to be taken by mouth even if it comes in a dropper bottle. If this medicine does not come in a dropper bottle, use a specially marked measuring spoon or other device to measure each dose accurately. The average household teaspoon may not hold the right amount of liquid.

• Do not use after the expiration date on the label. The medicine may not work properly after that date. If you have any questions about this, check with your pharmacist.

For patients taking the chewable tablet form of penicillins:

• Tablets should be chewed or crushed before they are swallowed.

To help clear up your infection completely, keep taking this medicine for the full time of treatment, even if you begin to feel better after a few days. If you have a "strep" infection, you should keep taking this medicine for at least 10 days. This is especially important in "strep" infections. Serious heart problems could develop later if your infection is not cleared up completely. Also, if you stop taking this medicine too soon, your symptoms may return.

This medicine works best when there is a constant amount in the blood or urine. To help keep the amount constant, do not miss any doses. Also, it is best to take the doses at evenly spaced times, day and night. For example, if you are to take 4 doses a day, the doses should be spaced about 6 hours apart. If this interferes with your sleep or other daily activities, or if you need help in planning the best times to take your medicine, check with your doctor, nurse, or pharmacist.

Storage -- To store this medicine:

• Keep out of the reach of children.

• Store away from heat and direct light.

• Do not store the capsule or tablet form of penicillins in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.

• Store the oral liquid form of penicillins in the refrigerator because heat will cause this medicine to break down. However, keep the medicine from freezing. Follow the directions on the label.

• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Dosing

Missed dose -- If you do miss a dose of this medicine, take it as soon as possible. This will help to keep a constant amount of medicine in the blood or urine. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Precautions While Using This Medicine

If your symptoms do not improve within a few days, or if they become worse, check with your doctor.

If you have ever had an allergic reaction to any of the penicillins, your doctor may want you to carry a medical identification (ID) card or wear a medical ID bracelet stating this.

In some patients, penicillins may cause diarrhea.
• Severe diarrhea may be a sign of a serious side effect. Do not take any diarrhea medicine without first checking with your doctor. Diarrhea medicines may make your diarrhea worse or make it last longer.

• For mild diarrhea, diarrhea medicine containing kaolin or attapulgite (e.g., Kaopectate tablets, Diasorb) may be taken. However, other kinds of diarrhea medicine should not be taken. They may make your diarrhea worse or make it last longer.

• If you have any questions about this or if mild diarrhea continues or gets worse, check with your doctor or pharmacist.

Oral contraceptives (birth control pills) containing estrogen may not work properly if you take them while you are taking ampicillin, bacampicillin, or penicillin V. Unplanned pregnancies may occur. You should use a different or additional means of birth control while you are taking any of these penicillins. If you have any questions about this, check with your doctor or pharmacist.

For diabetic patients:

• Amoxicillin, amoxicillin and clavulanate combination, ampicillin, ampicillin and sulbactam combination, bacampicillin, and penicillin G may cause false test results with some urine sugar tests. Check with your doctor before changing your diet or the dosage of your diabetes medicine.

Tell the doctor in charge that you are taking this medicine before you have any medical tests. The results of some tests may be affected by this medicine.

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Stop taking this medicine and get emergency help immediately if any of the following side effects occur:

Rare (may be less common with some penicillins)
Difficulty in breathing; lightheadedness; skin rash, hives, itching, or wheezing

In addition to the side effects mentioned above, check with your doctor immediately if any of the following side effects occur:

Rare (may be more common with some penicillins)
Abdominal or stomach cramps and pain (severe); abdominal bloating; blood in urine; convulsions (seizures); decreased amount of urine; diarrhea (watery and severe), which may also be bloody; fever; joint pain; sore throat and fever; unusual bleeding or bruising (some of the above side effects may also occur up to several weeks after you stop taking any of these medicines)

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

More common (may be less common with some penicillins)
Diarrhea (mild); nausea or vomiting; sore mouth or tongue

Overdose is very unlikely to occur with penicillins. However, if you think that you or someone else, especially a child, has taken too much, check with your doctor. Severe diarrhea, nausea, or vomiting may need to be treated.

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

*This information is reproduced from the Mayo Clinic Family Pharmacist v 2.0
Copyright 1994-1995 IVI Publishing Inc.

This information may not be complete and/or up to date.  Please do not use this as any sort of authoritative text for this drug.  Please consult with a physician before taking this or any drug.  This is presented only for reference usage within this site.