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Dynapen: Full Drug Profile

Medically reviewed by Min Clinic Staff | Updated: January 2026

Dynapen - General Information

One of the penicillins which is resistant to penicillinase. [PubChem]

 

Pharmacology of Dynapen

Dynapen is a beta-lactamase resistant penicillin similar to oxacillin. Dynapen has in vitro activity against gram-positive and gram-negative aerobic and anaerobic bacteria. The bactericidal activity of dicloxacillin results from the inhibition of cell wall synthesis and is mediated through dicloxacillin binding to penicillin binding proteins (PBPs). Dynapen is stable against hydrolysis by a variety of beta-lactamases, including penicillinases, and cephalosporinases and extended spectrum beta-lactamases.

 

Dynapen for patients

Patients receiving penicillins should be given the following information and instructions by the physician:

1. Patients should be told that penicillin is an antibacterial agent which will work with the body's natural defenses to control certain types of infections. They should be told that the drug should not be taken if they have had an allergic reaction to any form of penicillin previously, and to inform the physician of any allergies or previous allergic reactions to any drugs they may have had.

2. Patients who have previously experienced an anaphylactic reaction to penicillin should be instructed to wear a medical identification tag or bracelet.

3. Because most antibacterial drugs taken by mouth are best absorbed on an empty stomach, patients should be directed, unless circumstances warrant otherwise, to take penicillin one hour before meals or two hours after eating.

4. Patients should be told to take the entire course of therapy prescribed. even if fever and other symptoms have stopped.

5. If any of the following reactions occur stop taking your prescription and notify the physiclan shortness of breath wheezing, skin rash, mouth irritation, black tongue, sore throat, nausea, vomiting, diarrhea, fever, swollen joints or any unusual bleeding or bruising.

6. Do not take any additional medications without physician approval including nonprescription drugs such as antacids laxatives or vitamins.

7. Discard any liquid forms of penicillin after seven days if stored at room temperature or after 14 days it refrigerated.

 

Dynapen Interactions

Tetracycline, a bacteriostatic antibiotic, may antagonize the bactercidal effect of penicillin and concurrent use of these drugs should be avoided.

 

Dynapen Contraindications

A history of a hypersensitivity (anaphylactic) reaction to any penicillin is a contraindication.

 

Additional information about Dynapen

Dynapen Indication: Used to treat infections caused by penicillinase-producing staphylococci which have demonstrated susceptibility to the drug. Mechanism Of Action: Dynapen exerts a bactericidal action against penicillin-susceptible microorganisms during the state of active multiplication. All penicillins inhibit the biosynthesis of the bacterial cell wall. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, dicloxacillin inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins; it is possible that dicloxacillin interferes with an autolysin inhibitor. Drug Interactions: Anisindione The IV penicillin increases the anticoagulant effectDemeclocycline Possible antagonism of actionDicumarol The IV penicillin increases the anticoagulant effectDoxycycline Possible antagonism of actionEthinyl Estradiol This anti-infectious agent could decrease the effect of the oral contraceptiveMestranol This anti-infectious agent could decrease the effect of the oral contraceptiveMethacycline Possible antagonism of actionMinocycline Possible antagonism of actionWarfarin The IV penicillin increases the anticoagulant effectOxytetracycline Possible antagonism of actionRolitetracycline Possible antagonism of actionTetracycline Possible antagonism of actionMethotrexate The penicillin increases the effect and toxicity of methotrexateAcenocoumarol The IV penicillin increases the anticoagulant effect Food Interactions: Take on an empty stomach, food decreases the availability. Generic Name: Dicloxacillin Synonyms: Diclossacillina [DCIT]; Dicloxacilina [INN-Spanish]; Dicloxacillin Sodium; Dicloxacilline [INN-French]; Dicloxacillinum [INN-Latin]; Dicloxacilin; Dicloxacycline Drug Category: Anti-Bacterial Agents Drug Type: Small Molecule; Approved Other Brand Names containing Dicloxacillin: Dycill; Dynapen; Maclicine; Pathocil; Absorption: Absorption of the isoxazolyl penicillins after oral administration is rapid but incomplete: peak blood levels are achieved in 1-1.5 hours. Oral absorption of cloxacillin, dicloxacillin, oxacillin and nafcillin is delayed when the drugs are administered after meals. Toxicity (Overdose): Oral LD50 in rat is 3579 mg/kg. Symptoms of overexposure include irritation, rash, labored breathing, hives, itching, wheezing, nausea, chills, and fever. Protein Binding: Binds to serum protein, mainly albumin. Biotransformation: Not Available Half Life: The elimination half-life for dicloxacillin is about 0.7 hour. Dosage Forms of Dynapen: Capsule OralPowder, for solution Oral Chemical IUPAC Name: (2S,5R,6R)-6-[[3-(2,6-dichlorophenyl)-5-methyl1,2-oxazole-4-carbonyl]amino]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid Chemical Formula: C19H17Cl2N3O5S Dicloxacillin on Wikipedia: https://en.wikipedia.org/wiki/Dicloxacillin Organisms Affected: Enteric bacteria and other eubacteria