Sofkin

Sofkin is a semi-synthetic aminoglycoside antibiotic derived from kanamycin A. Similar to other aminoglycosides, Sofkin disrupts bacterial protein synthesis by binding to the 30S ribosome of susceptible organisms. Binding interferes with mRNA binding and tRNA acceptor sites leading to the production of non-functional or toxic peptides. Other mechanisms not fully understood may confer the bactericidal effects of Sofkin. Sofkin is also nephrotoxic and ototoxic.

Sofkin Sulfate Injection, USP is indicated in the short-term treatment of serious infections due to susceptible strains of Gram-negative bacteria, including Pseudomonas species, Escherichia coli, species of indole-positive and indole-negative Proteus, Providencia species, Klebsiella-Enterobacter-Serratia species, and Acinetobacter (Mima-Herellea) species.

Clinical studies have shown Sofkin Sulfate Injection, USP to be effective in bacterial septicemia (including neonatal sepsis); in serious infections of the respiratory tract, bones and joints, central nervous system (including meningitis) and skin and soft tissue; intra-abdominal infections (including peritonitis); and in burns and postoperative infections (including post-vascular surgery). Clinical studies have shown Sofkin also to be effective in serious complicated and recurrent urinary tract infections due to those organisms. Aminoglycosides, including Sofkin Sulfate Injection, USP are not indicated in uncomplicated initial episodes of urinary tract infections unless the causative organisms are not susceptible to antibiotics having less potential toxicity.

Bacteriologic studies should be performed to identify causative organisms and their susceptibilities to Sofkin. Sofkin may be considered as initial therapy in suspected Gram-negative infections and therapy may be instituted before obtaining the results of susceptibility testing. Clinical trials demonstrated that Sofkin was effective in infections caused by gentamicin and/or tobramycin-resistant strains of Gram-negative organisms, particularly Proteus rettgeri, Providencia stuartii, Serratia marcescens, and Pseudomonas aeruginosa. The decision to continue therapy with the drug should be based on results of the susceptibility tests, the severity of the infection, the response of the patient and the important additional considerations contained in the WARNINGS box above.

Sofkin has also been shown to be effective in staphylococci infections and may be considered as initial therapy under certain conditions in the treatment of known or suspected staphylococcal disease such as, severe infections where the causative organism may be either a Gram-negative bacterium or a staphylococcus, infections due to susceptible strains of staphylococci in patients allergic to other antibiotics, and in mixed staphylococci/Gram-negative infections.

In certain severe infections such as neonatal sepsis, concomitant therapy with a penicillin-type drug may be indicated because of the possibility of infections due to Gram-positive organisms such as streptococci or pneumococci.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Sofkin and other antibacterial drugs, Sofkin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Sofkin is an antibiotic. It fights bacteria in the body.

Sofkin is used to treat severe or serious bacterial infections.

Sofkin may also be used for purposes other than those listed in this medication guide.

The patient's pre-treatment body weight should be obtained for calculation of correct dosage. Sofkin may be given IM or IV.

The status of renal function should be estimated by measurement of the serum creatinine concentration or calculation of the endogenous creatinine clearance rate. The blood urea nitrogen (BUN) is much less reliable for this purpose. Reassessment of renal function should be made periodically during therapy.

Whenever possible, Sofkin concentrations in serum should be measured to assure adequate but not excessive levels. It is desirable to measure both peak and trough serum concentrations intermittently during therapy. Peak concentrations (30-90 min after injection) >35 mcg/mL and trough concentrations (just prior to the next dose) >10 mcg/mL should be avoided. Dosage should be adjusted as indicated.

IM: Patients with Normal Renal Function: The recommended dosage for adults, children and older infants with normal renal function is 15 mg/kg/day divided into 2 or 3 equal doses administered at equally-divided intervals ie, 7.5 mg/kg every 12 hrs or 5 mg/kg every 8 hrs. Treatment of patients in the heavier weight classes should not exceed 1.5 g/day.

When Sofkin is indicated in newborns, it is recommended that a loading dose of 10 mg/kg be administered initially to be followed with 7.5 mg/kg every 12 hrs.

The usual duration of treatment is 7-10 days. It is desirable to limit the duration of treatment to short term whenever feasible. The total daily dose by all routes of administration should not exceed 15 mg/kg/day. In difficult and complicated infections where treatment beyond 10 days is considered, the use of Sofkin should be re-evaluated. If continued, Sofkin serum levels, renal, auditory and vestibular functions should be monitored. At the recommended dosage level, uncomplicated infections due to Sofkin-sensitive organisms should respond in 24-48 hrs. If definite clinical response does not occur within 3-5 days, therapy should be stopped and the antibiotic susceptibility pattern of the invading organism should be rechecked. Failure of the infection to respond may be due to resistance of the organism or to the presence of septic foci requiring surgical drainage.

When Sofkin is indicated in uncomplicated urinary tract infections, a dose of 250 mg twice daily may be used.

IM: Patients with Impaired Renal Function: Whenever possible, serum Sofkin concentrations should be monitored by appropriate assay procedures. Doses may be adjusted in patients with impaired renal function either by administering normal doses at prolonged intervals or by administering reduced doses at a fixed interval.

Both methods are based on the patient's creatinine clearance or serum creatinine values since these have been found to correlate with aminoglycoside half-lives in patients with diminished renal function. These dosage schedules must be used in conjunction with careful clinical and laboratory observations of the patient and should be modified as necessary. Neither method should be used when dialysis is being performed.

Normal Dosage at Prolonged Intervals: If the creatinine clearance rate is not available and the patient's condition is stable, a dosage interval in hours for the normal dose can be calculated by multiplying the patient's serum creatinine by 9 eg, if the serum creatinine concentration is 2 mg/100 mL, the recommended single dose (7.5 mg/kg) should be administered every 18 hrs.

Reduced Dosage at Fixed Time Intervals: When renal function is impaired and it is desirable to administer Sofkin at a fixed time interval, dosage must be reduced. In these patients, serum Sofkin concentrations should be measured to assure accurate administration of Sofkin and to avoid concentrations >35 mcg/mL. If serum assay determinations are not available and the patient's condition is stable, serum creatinine and creatinine clearance values are the most readily available indicators of the degree of renal impairment to use as a guide for dosage.

First, initiate therapy by administering a normal dose, 7.5 mg/kg as a loading dose. This loading dose is the same as the normally recommended dose which would be calculated for a patient with normal renal function as described previously.

To determine the size of maintenance doses administered every 12 hrs, the loading dose should be reduced in proportion to the reduction in the patient's creatinine clearance rate: See equation.

An alternate rough guide for determining reduced dosage at 12-hr intervals (for patients whose steady-state serum creatinine values are known) is to divide the normally recommended dose by the patient's serum creatinine.

The previously mentioned dosage schedules are not intended to be rigid recommendations but are provided as guides to dosage when the measurement of Sofkin serum levels is not feasible.

IV: The individual dose, the total daily dose and the total cumulative dose of Sofkin are identical to the dose recommended for IM administration. The solution for IV use is prepared by adding the contents of a 500-mg vial to 100 or 200 mL of sterile diluent eg, 0.9% Sodium Chloride Injection or 5% Dextrose Injection or any of the compatible solutions listed as follows.

The solution is administered to adults over a 30- to 60-min period. The total daily dose should not exceed 15 mg/kg/day and may be divided into either 2 or 3 equally divided doses at equally divided intervals.

Children: The amount of fluid used will depend on the amount of Sofkin ordered for the patient. It should be a sufficient amount to infuse the Sofkin over a 30- to 60-min period. Infants should receive a 1- to 2-hr infusion.

See also:
What is the most important information I should know about Sofkin?

If you are injecting Sofkin at home, your healthcare provider will give you detailed instructions on how and where to inject the medication. If you do not understand these directions, do not attempt to inject the medication. Contact your healthcare provider for further instructions.

Sofkin may cause damage to the kidneys and/or nerves. Kidney function and drug levels in the blood may be monitored with blood tests during treatment. Tell your doctor if you experience hearing loss, dizziness, numbness, skin tingling, muscle twitching, or seizures which may be signs of nerve damage.

Use Sofkin as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Sofkin is usually administered as an injection at your doctor's office, hospital, or clinic. If you are using Sofkin at home, carefully follow the injection procedures taught to you by your health care provider.
• If Sofkin contains particles or is discolored, or if the vial is cracked or damaged in any way, do not use it.
• Do not mix penicillin antibiotics (eg, ampicillin) in the same container or administer at the same time as Sofkin.
• Drinking extra fluids while you are taking Sofkin is recommended. Check with your doctor or nurse for instructions.
• To clear up your infection completely, continue using Sofkin for the full course of treatment even if you feel better in a few days. Do not miss any doses.
• Keep this product, as well as syringes and needles, out of the reach of children. Do not reuse needles, syringes, or other materials. Dispose of properly after use. Ask your doctor, nurse, or pharmacist to explain local regulations for proper disposal.
• If you miss a dose of Sofkin, use it as soon as possible. Check with your doctor, nurse, or pharmacist for instructions on scheduling other doses.

Ask your health care provider any questions you may have about how to use Sofkin.

Use: Labeled Indications

Serious infections: Treatment of serious infections (eg, bone infections, respiratory tract infections, endocarditis, septicemia) due to gram-negative organisms, including Pseudomonas, Escherichia coli, Proteus, Providencia, Klebsiella, Enterobacter, Serratia, and Acinetobacter

Off Label Uses

Cystic fibrosis exacerbation (aerosolized Sofkin)

The use of aerosolized Sofkin for cystic fibrosis exacerbations has not been well studied. There is evidence to support the use of aerosolized Sofkin to eradicate P. aeruginosa, Mycobacterium abscessus, and Mycobacterium avium complex in patients with cystic fibrosis when used as adjunctive therapy with Sofkin IV and ceftazidime. A Society of Infectious Diseases Pharmacists consensus summary does not recommend routine use of aerosolized antibiotics to treat acute cystic fibrosis exacerbations.

Mycobacterium avium complex (MAC)

Based on an official statement on the diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases from the American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA), Sofkin (or streptomycin) for the first 2 to 3 months of therapy in combination with a macrolide, rifamycin, and ethambutol is effective and recommended for the treatment of extensive Mycobacterium avium complex (MAC) disease, especially fibrocavitary or severe nodular/bronchiectatic disease, or patients who have failed prior drug therapy.

Tuberculosis

According to the American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America joint guidelines on the treatment of tuberculosis (TB), intravenous (IV) or intramuscular (IM) Sofkin can be used as second-line therapy for patients with drug-resistant TB whose isolate has demonstrated presumed susceptibility to Sofkin.

See also:
What other drugs will affect Sofkin?

Additive effect w/ other neurotoxic, ototoxic or nephrotoxic agents (e.g. bacitracin, cisplatin, amphotericin B, ciclosporin, tacrolimus, cefaloridine, paromomycin, viomycin, polymyxin B, colistin, vancomycin, and other aminoglycosides). Enhanced toxicity w/ rapidly acting diuretics (e.g. furosemide, ethacrynic acid). Increased creatinine serum level w/ cephalosporins. Indomethacin may increase the plasma concentration of Sofkin in neonates. Increased risk of hypocalcaemia w/ biphosphonates. Increased risk of nephrotoxicity and possibly ototoxicity w/ platinum compounds. Increased risk of neuromuscular blockade and consequent resp depression w/ anaesth or muscle relaxants (e.g. ether, halothane, d-tubocurarine, succinylcholine decamethonium, atracurium, rocuronium, vecuronium).

See also:
What are the possible side effects of Sofkin?

Applies to Sofkin: injection solution

In addition to its needed effects, some unwanted effects may be caused by Sofkin (the active ingredient contained in Sofkin). In the event that any of these side effects do occur, they may require medical attention.

If any of the following side effects occur while taking Sofkin, check with your doctor or nurse immediately:

Incidence not known:

• Agitation
• black, tarry stools
• bloody or cloudy urine
• bluish lips or skin
• blurred vision
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• chest pain
• chills
• coma
• confusion
• cough
• decrease in the amount of urine
• decreased urine output
• depression
• difficulty with breathing
• difficulty with moving
• dizziness
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• drowsiness
• dry mouth
• feeling of fullness in the ears
• fever
• headache
• hearing loss
• irritability
• lethargy
• loss of balance
• loss or change in hearing
• muscle pain or stiffness
• muscle twitching
• nausea
• not breathing
• pain in the joints
• pain in the lower back or side
• painful or difficult urination
• pale skin
• rapid weight gain
• ringing or buzzing in the ears
• seizures
• shakiness in the legs, arms, hands, or feet
• shortness of breath
• sore throat
• sores, ulcers, or white spots on the lips or in the mouth
• stupor
• sweating
• swelling of the face, ankles, or hands
• swollen glands
• thirst
• trembling or shaking of the hands or feet
• trouble with hearing
• troubled breathing with exertion
• unusual bleeding or bruising
• unusual tiredness or weakness

Minor Side Effects

Some of the side effects that can occur with Sofkin may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

Incidence not known:

• Skin rash
• vomiting