Dicloxacillin is a narrow-spectrum

β-lactam antibiotic β-lactam antibiotics (beta-lactam antibiotics) are antibiotics that contain a beta-lactam ring in their chemical structure. This includes penicillin derivatives (penams), cephalosporins and cephamycins (cephems), monobactams, carbapenems and ...

of the

penicillin Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from '' Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum usin ...

class. It is used to treat infections caused by susceptible (non-resistant)

Gram-positive bacteria In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bac ...

.Product Information: DICLOXACILLIN SODIUM-dicloxacillin sodium capsule. Teva Pharmaceuticals USA Inc, Revised 8/2015 It is active against

beta-lactamase Beta-lactamases, (β-lactamases) are enzymes () produced by bacteria that provide multi-resistance to beta-lactam antibiotics such as penicillins, cephalosporins, cephamycins, monobactams and carbapenems ( ertapenem), although carbap ...

-producing organisms such as ''

Staphylococcus aureus ''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often posit ...

'', which would otherwise be resistant to most

s. Dicloxacillin is available under a variety of trade names including Diclocil ( BMS). It was patented in 1961 and approved for medical use in 1968.

Medical uses

Dicloxacillin is used to treat mild-to-moderate staphylococcal infections. To decrease the development of resistance, dicloxacillin is recommended to treat infections that are suspected or proven to be caused by beta-lactamase-producing bacteria. Dicloxacillin is similar in

pharmacokinetics Pharmacokinetics (from Ancient Greek ''pharmakon'' "drug" and ''kinetikos'' "moving, putting in motion"; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to determining the fate of substances administered ...

, antibacterial activity, and indications to flucloxacillin, and the two agents are considered interchangeable.Rossi S, editor. Australian Medicines Handbook 2006. Adelaide: Australian Medicines Handbook; 2006 It is believed to have lower incidence of severe hepatic

adverse effects An adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. The term complica ...

than flucloxacillin, but a higher incidence of renal adverse effects. Dicloxacillin is used for the treatment of infections caused by susceptible bacteria. Specific approved indications include: * Staphylococcal skin infections and

cellulitis Cellulitis is usually a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of ...

– including

impetigo Impetigo is a bacterial infection that involves the superficial skin. The most common presentation is yellowish crusts on the face, arms, or legs. Less commonly there may be large blisters which affect the groin or armpits. The lesions may be pa ...

otitis externa Otitis externa, also called swimmer's ear, is inflammation of the ear canal. It often presents with ear pain, swelling of the ear canal, and occasionally decreased hearing. Typically there is pain with movement of the outer ear. A high fever is ...

folliculitis Folliculitis is the infection and inflammation of one or more hair follicles. The condition may occur anywhere on hair-covered skin. The rash may appear as pimples that come to white tips on the face, chest, back, arms, legs, buttocks, or head. A ...

boil A boil, also called a furuncle, is a deep folliculitis, which is an infection of the hair follicle. It is most commonly caused by infection by the bacterium '' Staphylococcus aureus'', resulting in a painful swollen area on the skin caused by ...

carbuncles A carbuncle is a cluster of boils caused by bacterial infection, most commonly with ''Staphylococcus aureus'' or ''Streptococcus pyogenes''. The presence of a carbuncle is a sign that the immune system is active and fighting the infection. Th ...

, and

mastitis Mastitis is inflammation of the breast or udder, usually associated with breastfeeding. Symptoms typically include local pain and redness. There is often an associated fever and general soreness. Onset is typically fairly rapid and usually occurs ...

Pneumonia Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severit ...

(adjunct) *

Osteomyelitis Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children e.g. the femur and humerus, while the ...

septic arthritis Acute septic arthritis, infectious arthritis, suppurative arthritis, osteomyelitis, or joint infection is the invasion of a joint by an infectious agent resulting in joint inflammation. Generally speaking, symptoms typically include redness, h ...

, throat infections, streptococcus *

Septicaemia Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...

Empirical Empirical evidence for a proposition is evidence, i.e. what supports or counters this proposition, that is constituted by or accessible to sense experience or experimental procedure. Empirical evidence is of central importance to the sciences and ...

treatment for

endocarditis Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or the ...

*Surgical

prophylaxis Preventive healthcare, or prophylaxis, consists of measures taken for the purposes of disease prevention.Hugh R. Leavell and E. Gurney Clark as "the science and art of preventing disease, prolonging life, and promoting physical and mental hea ...

Available forms

Dicloxacillin is commercially available as the sodium salt, dicloxacillin sodium, in capsules and as a powder for reconstitution.

Contraindications

Dicloxacillin is contraindicated in those with a previous history of allergy (hypersensitivity/ anaphylactic reaction) to any penicillins.

Adverse effects

Common

adverse drug reaction An adverse drug reaction (ADR) is a harmful, unintended result caused by taking medication. ADRs may occur following a single dose or prolonged administration of a drug or result from the combination of two or more drugs. The meaning of this term ...

s (ADRs) associated with the use of dicloxacillin include:

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of th ...

rash A rash is a change of the human skin which affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, c ...

urticaria Hives, also known as urticaria, is a kind of skin rash with red, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and does not leave any long-last ...

pain Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, ...

and

inflammation Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molec ...

at injection site,

superinfection A superinfection is a second infection superimposed on an earlier one, especially by a different microbial agent of exogenous or endogenous origin, that is resistant to the treatment being used against the first infection. Examples of this in bact ...

(including candidiasis),

allergy Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derm ...

, and transient increases in liver enzymes and bilirubin. On rare occasions,

cholestatic jaundice Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme metab ...

(also referred to as cholestatic hepatitis) has been associated with dicloxacillin therapy. The reaction may occur up to several weeks after treatment has stopped, and takes weeks to resolve. The estimated incidence is 1 in 15,000 exposures, and is more frequent in people over 55 years old, females, and those with treatment longer than 2 weeks. It should be used with caution and monitored in the elderly, particularly with intravenous administration, due to a risk of

thrombophlebitis Thrombophlebitis is a phlebitis (inflammation of a vein) related to a thrombus (blood clot). When it occurs repeatedly in different locations, it is known as thrombophlebitis migrans (migratory thrombophlebitis). Signs and symptoms The following s ...

. Dicloxacillin can also lower the effectiveness of birth control pills and pass into breast milk.

Interactions

Dicloxacillin has potential interactions with following drugs: * Warfarin * Methotrexate * Tetracyclines

Resistance

Despite dicloxacillin being insensitive to beta-lactamases, some organisms have developed resistance to other narrow-spectrum β-lactam antibiotics including methicillin. Such organisms include methicillin-resistant ''Staphylococcus aureus'' (MRSA).

Mechanism of action

Like other β-lactam antibiotics, dicloxacillin acts by inhibiting the synthesis of bacterial

cell wall A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mec ...

s. It inhibits cross-linkage between the linear

peptidoglycan Peptidoglycan or murein is a unique large macromolecule, a polysaccharide, consisting of sugars and amino acids that forms a mesh-like peptidoglycan layer outside the plasma membrane, the rigid cell wall (murein sacculus) characteristic of most ba ...

polymer chains that make up a major component of the cell wall of

Gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bact ...

bacteria.

Medicinal chemistry

Dicloxacillin is insensitive to

(also known as penicillinase) enzymes secreted by many penicillin-resistant bacteria. The presence of the isoxazolyl group on the side chain of the penicillin nucleus facilitates the β-lactamase resistance, since they are relatively intolerant of side-chain

steric hindrance Steric effects arise from the spatial arrangement of atoms. When atoms come close together there is a rise in the energy of the molecule. Steric effects are nonbonding interactions that influence the shape ( conformation) and reactivity of ions ...

. Thus, it is able to bind to

penicillin-binding protein Penicillin-binding proteins (PBPs) are a group of proteins that are characterized by their affinity for and binding of penicillin. They are a normal constituent of many bacteria; the name just reflects the way by which the protein was disc ...

s (PBPs) and inhibit

crosslinking, but is not bound by or inactivated by β-lactamase

References

{{Xenobiotic-sensing receptor modulators Penicillins Enantiopure drugs Isoxazoles Chlorobenzenes