cloxacillin

Bind to bacterial cell wall, leading to cell death. Not inactivated by penicillinase enzymes.

Therapeutic effects:

Bactericidal action.

Spectrum:

Active against most gram-positive aerobic cocci.
Spectrum is notable for activity against:
- Penicillinase-producing strains of Staphylococcus aureus and Staphylococcus epidermidis.
Not active against methicillin-resistant Staphylococcus aureus.

Pharmacokinetics ⬆ ⬇

Absorption: IV administration results in complete bioavailability. Moderately absorbed (50%) following oral administration.

Distribution: Widely distributed; penetration into CSF is minimal but sufficient in the presence of inflamed meninges.

Metabolism/Excretion: Some metabolism by the liver (9—22%) and some renal excretion of unchanged drug (20%).

Half-Life: 0.5—1.1 hr (↑ in severe hepatic impairment, renal impairment, and neonates).

Time/Action Profile ⬆ ⬇

ROUTE	ONSET	PEAK	DURATION
PO	30 min	30—120 min	6 hr
IM	unknown	unknown	6 hr
IV	rapid	end of injection/infusion	6 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Previous hypersensitivity to penicillin (cross-sensitivity exists with cephalosporins and other beta-lactam antibiotics).

Use Cautiously in:

Severe renal impairment;
Severe hepatic impairment;
OB: Safety and effectiveness not established in pregnancy;
Lactation: Safety and effectiveness not established in breastfeeding;
Pedi: Safety and effectiveness not established in premature and newborn infants.

Adv. Reactions/Side Effects ⬆ ⬇

Derm: rash, urticaria

GI: diarrhea, epigastric distress, nausea, vomiting, CLOSTRIDIOIDES DIFFICILE-ASSOCIATED DIARRHEA (CDAD)

GU: interstitial nephritis

Hemat: eosinophilia, leukopenia

Neuro: SEIZURES

Misc: HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS AND SERUM SICKNESS), superinfection

Interactions ⬆ ⬇

Drug-drug:

May ↓ effectiveness of oral contraceptive agents.
Probenecid↓ renal excretion and ↑ levels (therapy may be combined for this purpose).
May ↑ levels and risk of toxicity of methotrexate.

Drug-Food:

Food ↓ oral absorption by 50%.

Route/Dosage ⬆ ⬇

PO (Adults ): 250—500 mg every 6 hr.
PO (Children ≥40 kg): 250—500 mg every 6 hr (max dose = 6 g/day).
PO (Children 5—<40 kg): 50 mg/kg/day divided every 6 hr (max dose = 4 g/day).
IM IV (Adults ): 1—2 g every 4—6 hr.
IM IV (Children ): 100—200 mg/kg/day in divided doses every 6 hr (max = 2 g/dose).

Availability ⬆ ⬇

Capsules: 250 mg; 500 mg
Oral solution: 125 mg/5 mL
Lyophilized powder for injection: 250 mg/vial; 500 mg/vial; 1 g/vial; 2 g/vial

Assessment ⬆ ⬇

Assess for infection (vital signs; appearance of wound, sputum, urine, and stool) initially and during therapy.
Obtain a history before initiating therapy to determine previous use of and reactions to cephalosporins or other beta-lactam antibiotics. Patients with no history of penicillin sensitivity may still have an allergic response.
Assess for hypersensitivity reactions (anaphylaxis, rash, pruritus, laryngeal edema, wheezing, abdominal pain). If hypersensitivity reaction occurs, discontinue cloxacillin and notify health care provider immediately. Implement emergent supportive measures (epinephrine) as indicated.
Monitor bowel function and assess for CDAD (diarrhea, abdominal cramping, fever, bloody stools). Notify health care provider promptly. May begin up to several weeks following cessation of therapy.

Lab Test Considerations:

Obtain specimens for culture and sensitivity before initiating therapy. 1st dose may be given before receiving results.
- May cause leukopenia and neutropenia, especially with prolonged therapy or hepatic impairment.
- May cause positive direct Coombs test result.
- May ↑ AST, ALT, LDH, and alkaline phosphatase.

Implementation ⬆ ⬇

PO: Administer around the clock on an empty stomach ≥1 hr before or 2 hr after meals. Take with 8 ounces of water. Acidic juices may ↓ absorption of penicillins. DNC: Swallow whole. Do not crush, chew, or open capsules.
- Use calibrated measuring device for liquid preparations. Shake well. Solution is stable for 14 days if refrigerated.
IM: Reconstitution: Reconstitute 250-mg and 500-mg vials with 1.9 mL and 1.7 mL, respectively, of sterile water for injection. Shake well to dissolve. Stable for 24 hr at room temperature or 48 hr if refrigerated. Concentration: 125 mg/mL (250-mg vial) and 250 mg/mL (500-mg vial).
Y-Site Compatibility:
- acetylcysteine
- acyclovir
- aminophylline
- amiodarone
- amphotericin B liposomal
- atropine
- benztropine
- caffeine citrate
- calcium chloride
- calcium gluconate
- caspofungin
- cefazolin
- ceftazidime
- ceftriaxone
- cefotaxime
- cefoxitin
- cefuroxime
- chloramphenicol
- chlorothiazide
- clindamycin
- cyclophosphamide
- cyclosporine
- dexamethasone
- digoxin
- dopamine
- epinephrine
- edetate calcium disodium
- esmolol
- fentanyl
- fluconazole
- furosemide
- heparin
- hydrocortisone
- insulin regular
- isoproterenol
- ketamine
- levofloxacin
- lidocaine
- magnesium sulfate
- mannitol
- meropenem
- methohexital
- methylprednisolone
- metoclopramide
- metronidazole
- milrinone
- naloxone
- nitroprusside
- norepinephrine
- ondansetron
- oxytocin
- penicillin G
- phenobarbital
- phentolamine
- piperacillin/tazobactam
- potassium chloride
- procainamide
- prochlorperazine
- propranolol
- sildenafil
- sodium bicarbonate
- succinylcholine
- sufentanil
- voriconazole
Y-Site Incompatibility:
- amikacin
- azithromycin
- blinatumomab
- chlorpromazine
- ciprofloxacin
- diazepam
- diphenhydramine
- dobutamine
- droperidol
- labetalol
- lorazepam
- midazolam
- morphine
- nitroglycerin
- phenytoin
- potassium phosphates
- rocuronium
- trimethoprim/sulfamethoxazole
- tobramycin

IV Administration:

Intermittent Infusion: Reconstitution: Reconstitute 1-g and 2-g vials with 3.4 mL and 6.8 mL, respectively, of sterile water for injection. Add to an appropriate infusion fluid in amount calculated to give desired dose. Shake well to dissolve. Use solution immediately. Concentration: Concentration: 250 mg/mL. Rate: Infuse over 30–40 min.

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of medication to patient. Advise patient to read Patient Information before starting therapy. Advise patient to take medication around the clock and to finish the drug completely as directed, even if feeling better. Missed doses should be taken as soon as remembered. Advise patient that sharing of this medication may be dangerous.
Advise patient to notify health care provider of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care provider before taking other medications.
Advise patient to report signs of superinfection (black, furry overgrowth on the tongue; vaginal itching or discharge; loose or foul-smelling stools) and allergy.
Advise patient to notify health care provider if fever and diarrhea develop, especially if stool contains blood, pus, or mucus. Advise patient not to treat diarrhea without consulting health care provider.
Advise patient to notify health care provider if symptoms do not improve.
Rep: Advise women of reproductive potential to notify health care provider if pregnancy is planned or suspected or if breastfeeding. Advise patient taking oral contraceptives to use an additional nonhormonal method of contraception during therapy with penicillin and until next menstrual period.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇