Kanamycin

Serious Bacterial Infections

Kanamycin is primarily used for the short-term treatment of serious infections caused by susceptible strains of Gram-negative bacteria. It is often prescribed for the following conditions:

• Respiratory tract infections
• Bone and joint infections
• Skin and soft tissue infections
• Intra-abdominal infections, such as peritonitis
• Septicemia (bloodstream infections)

Tuberculosis Treatment

This medication may be used as a second-line treatment for tuberculosis (TB). It is typically administered in combination with other drugs when standard first-line treatments are not effective or cannot be tolerated by the patient.

Other Uses

Kanamycin is sometimes used to suppress bacteria in the intestines. This may be done to prepare the bowel for surgery or as part of the management of hepatic coma to reduce the levels of ammonia-producing bacteria in the gut.

Mechanism of Action

Kanamycin belongs to a group of medicines called aminoglycosides. It works by entering bacterial cells and binding to specific structures called ribosomes, which are responsible for protein synthesis.

Once attached, the medication interferes with the bacteria's ability to read genetic instructions correctly. This leads to several outcomes:

• The bacteria may stop producing essential proteins altogether.
• The bacteria may produce abnormal or non-functional proteins.
• The protective outer layers of the bacteria may become damaged.

Because bacteria cannot maintain their structure or perform vital functions without these proteins, they eventually die. This process makes kanamycin a bactericidal antibiotic, meaning it kills the bacteria directly rather than just preventing them from spreading.

Common Side Effects

Some side effects may occur that usually do not require immediate medical attention unless they persist or become bothersome. These include:

• Nausea
• Vomiting
• Diarrhea
• Pain, irritation, or redness at the site of injection

Serious Side Effects

Kanamycin can cause severe reactions. You should contact your healthcare provider immediately if you experience any of the following symptoms:

Hearing and Balance Problems

• Ringing in the ears (tinnitus)
• A feeling of fullness in the ears
• Partial or total hearing loss
• Dizziness or a spinning sensation (vertigo)
• Loss of balance or clumsiness

Kidney Issues

• Significant decrease in the amount or frequency of urination
• Increased thirst
• Loss of appetite
• Blood in the urine

Nervous System and Muscle Effects

• Numbness or tingling in the hands, feet, or face
• Muscle twitching or tremors
• Muscle weakness
• Seizures

Allergic Reactions

• Skin rash, itching, or hives
• Swelling of the face, lips, or tongue
• Difficulty breathing or wheezing

Boxed Warnings

Kanamycin carries several serious warnings regarding potential toxicity:

• Hearing and Balance Loss: This medication can cause permanent damage to the nerves used for hearing and balance (ototoxicity). Symptoms may include ringing in the ears, dizziness, or hearing loss. These effects can continue to progress even after the medication is stopped.
• Kidney Damage: Kanamycin can cause significant kidney problems (nephrotoxicity). Healthcare providers typically monitor kidney function through blood and urine tests during treatment.
• Neuromuscular Blockade: In some cases, the drug may cause muscle weakness or difficulty breathing (respiratory paralysis), especially when used alongside certain anesthetics or muscle relaxants.

Precautions and Risks

The risk of toxic effects is higher in individuals with pre-existing kidney impairment, those receiving high doses, or those undergoing long-term treatment. Dehydration can also increase the risk of kidney damage while taking this medication.

Pregnancy and Fetal Risk

Kanamycin can cause harm to a developing fetus. There have been reports of total, irreversible, bilateral congenital deafness in children whose mothers received similar aminoglycoside antibiotics during pregnancy. It should only be used during pregnancy if the potential benefit justifies the risk to the fetus.

Drug Interactions

The risk of toxicity increases if kanamycin is used at the same time as other medications that can damage the kidneys or nerves. This includes other aminoglycoside antibiotics and certain potent diuretics (water pills) like furosemide or ethacrynic acid, which may increase the concentration of the drug in the blood.

Allergic Reactions

Kanamycin is contraindicated in individuals with a known history of hypersensitivity or serious toxic reactions to kanamycin or other aminoglycoside antibiotics, as cross-sensitivity between these drugs may occur.

Pregnancy

Kanamycin belongs to a class of antibiotics called aminoglycosides. These medications are known to cross the placenta and reach the developing fetus. Clinical evidence suggests that aminoglycosides may cause irreversible, bilateral congenital deafness (permanent hearing loss) in children whose mothers received similar medications during pregnancy. There is also a potential risk of kidney damage to the fetus.

Because of these risks, healthcare providers typically only use kanamycin during pregnancy if the mother's condition is life-threatening or if other, safer antibiotics are not effective.

Breastfeeding

Small amounts of kanamycin are excreted into breast milk. While the specific effects on nursing infants are not fully documented, there is a potential for serious adverse reactions. Healthcare providers generally recommend that a decision be made to either stop breastfeeding or stop the medication, taking into account the importance of the drug to the mother's health.

Consult Your Healthcare Provider

It is important for patients to inform their healthcare provider if they are pregnant, planning to become pregnant, or breastfeeding before starting treatment with kanamycin. A medical professional can help weigh the potential risks to the fetus or infant against the benefits of the treatment.

Available Forms

Kanamycin is provided in several formulations for different methods of administration:

• Injectable Solution: This is a sterile aqueous solution intended for parenteral use. It can be administered via intramuscular injection or intravenous infusion.
• Pediatric Injection: A specific formulation of the injectable solution is available for use in pediatric patients.
• Oral Capsules: Kanamycin is also available in a capsule form to be taken by mouth, typically used for localized action in the digestive tract.

FDA Approval Status

Kanamycin was originally approved by the U.S. Food and Drug Administration (FDA) for the short-term treatment of serious infections caused by susceptible bacteria. While the drug remains on the FDA's list of approved drugs, many brand-name versions, such as Kantrex, have been discontinued by their manufacturers for reasons not related to safety or efficacy. Its clinical use has largely been superseded by other aminoglycosides with more favorable safety profiles.

Boxed Warnings

The FDA requires a boxed warning for kanamycin due to the potential for severe toxicities. These warnings include:

• Ototoxicity: Kanamycin can cause permanent hearing loss and damage to the vestibular system (balance). This risk is increased in patients with kidney impairment or those receiving high doses for extended periods.
• Nephrotoxicity: The drug is known to be toxic to the kidneys. Patients must be monitored closely for changes in renal function during therapy.
• Neuromuscular Blockade: Kanamycin may cause respiratory paralysis, particularly when administered following the use of anesthesia or muscle relaxants.

Regulatory Guidance

Due to its toxicity profile, regulatory labeling specifies that kanamycin should be reserved for serious infections where other less toxic antibiotics are ineffective or cannot be used. The FDA recommends that treatment be limited to short durations and that drug serum concentrations be monitored to minimize the risk of adverse effects.

Risks to the Fetus

Kanamycin is generally not recommended for use during pregnancy because it can cause serious harm to the developing baby. It belongs to a class of antibiotics known as aminoglycosides, which are capable of crossing the placenta. These drugs have been linked to permanent damage to the nerves in the ear, potentially leading to irreversible hearing loss or deafness in the child.

Because of these risks, healthcare providers typically only use kanamycin in pregnant patients when the infection is life-threatening and no safer treatment options are available. If you are pregnant or planning to become pregnant, you must inform your doctor before starting this medication.

• Hearing Loss: There is a known risk of congenital deafness associated with this class of antibiotics when used during pregnancy.
• Medical Necessity: Use is usually limited to severe cases where other antibiotics are not effective or cannot be used.