Cefdinir, sold under the brand name Omnicef among others, is an

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

used to treat bacterial infections including bacterial

pneumonia Pneumonia is an Inflammation, inflammatory condition of the lung primarily affecting the small air sacs known as Pulmonary alveolus, alveoli. Symptoms typically include some combination of Cough#Classification, productive or dry cough, ches ...

, other respiratory tract infections,

otitis media Otitis media is a group of Inflammation, inflammatory diseases of the middle ear. One of the two main types is acute otitis media (AOM), an infection of rapid onset that usually presents with ear pain. In young children this may result in pullin ...

strep throat Streptococcal pharyngitis, also known as streptococcal sore throat (strep throat), is pharyngitis (an infection of the pharynx, the back of the throat) caused by ''Streptococcus pyogenes'', a Gram-positive bacteria, gram-positive, group A str ...

, 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 ...

. It may also be used as an alternative antibiotic for those with a severe

penicillin allergy The side effects of penicillin are bodily responses to penicillin and closely related antibiotics that do not relate directly to its effect on bacteria. A side effect is an effect that is not intended with normal dosing. Some of these reactions a ...

. It is taken by mouth. Common side effects include diarrhea, nausea, and a skin rash. Serious side effects may include ''Clostridioides difficile'' infection,

anaphylaxis Anaphylaxis (Greek: 'up' + 'guarding') is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of the use of emergency medication on site. It typicall ...

, and

Stevens–Johnson syndrome Stevens–Johnson syndrome (SJS) is a type of severe skin reaction. Together with toxic epidermal necrolysis (TEN) and #Classification, Stevens–Johnson/toxic epidermal necrolysis (SJS/TEN) overlap, they are considered febrile mucocutaneous d ...

. Use in

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

and

breastfeeding Breastfeeding, also known as nursing, is the process where breast milk is fed to a child. Infants may suck the milk directly from the breast, or milk may be extracted with a Breast pump, pump and then fed to the infant. The World Health Orga ...

is believed to be safe but has not been well studied. It is a third-generation cephalosporin antibiotic and works by interfering with a bacteria's ability to make a

cell wall A cell wall is a structural layer that surrounds some Cell type, cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, ...

, resulting in its death.

Medical uses

Therapeutic uses of cefdinir include

soft tissue Soft tissue connective tissue, connects and surrounds or supports internal organs and bones, and includes muscle, tendons, ligaments, Adipose tissue, fat, fibrous tissue, Lymphatic vessel, lymph and blood vessels, fasciae, and synovial membranes.� ...

infections, and respiratory tract infections including

sinusitis Sinusitis, also known as rhinosinusitis, is an inflammation of the mucous membranes that line the sinuses resulting in symptoms that may include production of thick nasal mucus, nasal congestion, facial congestion, facial pain, facial pressure ...

(for

penicillin Penicillins (P, PCN or PEN) are a group of beta-lactam antibiotic, β-lactam antibiotics originally obtained from ''Penicillium'' Mold (fungus), moulds, principally ''Penicillium chrysogenum, P. chrysogenum'' and ''Penicillium rubens, P. ru ...

-allergic patients),

community-acquired pneumonia Community-acquired pneumonia (CAP) refers to pneumonia contracted by a person outside of the healthcare system. In contrast, hospital-acquired pneumonia (HAP) is seen in patients who are in a hospital or who have recently been hospitalized in the ...

, and acute exacerbations of

bronchitis Bronchitis is inflammation of the bronchi (large and medium-sized airways) in the lungs that causes coughing. Bronchitis usually begins as an infection in the nose, ears, throat, or sinuses. The infection then makes its way down to the bronchi. ...

Susceptible organisms

Cefdinir is a

bactericidal A bactericide or bacteriocide, sometimes abbreviated Bcidal, is a substance which kills bacteria. Bactericides are disinfectants, antiseptics, or antibiotics. However, material surfaces can also have bactericidal properties based solely on their p ...

of the

cephalosporin The cephalosporins (sg. ) are a class of β-lactam antibiotics originally derived from the fungus '' Acremonium'', which was previously known as ''Cephalosporium''. Together with cephamycins, they constitute a subgroup of β-lactam antibio ...

class of antibiotics. It can be used to treat infections caused by several

Gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

and

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. The Gram stain is ...

bacteria.

Bacterial susceptibility and resistance

Cefdinir is a

broad-spectrum antibiotic A broad-antimicrobial spectrum, spectrum antibiotic is an antibiotic that acts on the two major bacterial groups, Gram-positive and Gram-negative, or any antibiotic that acts against a wide range of disease-causing bacteria. These medications are ...

and has been used to treat infections of the respiratory tract including pneumonia, sinusitis, and bronchitis. The following represents MIC susceptibility data for a few medically significant microorganisms. * ''Haemophilus influenzae'': 0.05 - 4 μg/ml * ''Streptococcus pneumoniae'': 0.006 - 64 μg/ml * ''Streptococcus pyogenes'': ≤0.004 - 2 μg/ml

Available forms

Cefdinir is administered orally. It is available as capsules and a suspension. The dosage, schedule, and duration of therapy vary according to the type of infection. It is available under several brand names and as a

generic medication A generic drug is a pharmaceutical drug that contains the same chemical substance as a drug that was originally protected by chemical patents. Generic drugs are allowed for sale after the patents on the original drugs expire. Because the active ch ...

Side effects

Side effects of cefdinir include diarrhea, vaginal infections or inflammation, nausea, headache, and abdominal pain." It is also one of the medications that can cause

toxic epidermal necrolysis Toxic epidermal necrolysis (TEN), also known as Lyell's syndrome, is a type of severe skin reaction. Together with Stevens–Johnson syndrome (SJS) it forms a spectrum of disease, with TEN being more severe. Early symptoms include fever and f ...

. The pediatric version of cefdinir can bind to iron in the digestive tract; in rare cases, this causes rust or red discoloration of the stool. Blood typically appears dark brown or black in stool, and testing may confirm which is present. If the reddish stool is accompanied by abdominal pain, weight loss, diarrhea, etc., a ''

Clostridioides difficile ''Clostridioides difficile'' ( syn. ''Clostridium difficile'') is a bacterium known for causing serious diarrheal infections, and may also cause colon cancer. It is known also as ''C. difficile'', or ''C. diff'' (), and is a Gram-positive spec ...

'' infection caused by the antibiotic could be signified.

Mechanism of action

Synthesis

Acylation In chemistry, acylation is a broad class of chemical reactions in which an acyl group () is added to a substrate. The compound providing the acyl group is called the acylating agent. The substrate to be acylated and the product include the foll ...

at the primary amine of the cephalosporin intermediate (1) with 4-bromo-3-oxobutanoyl bromide (2) gives the amide (3). The active

methylene group A methylene group is any part of a molecule that consists of two hydrogen atoms bound to a carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—m ...

in that compound is then nitrosated with

sodium nitrite Sodium nitrite is an inorganic compound with the chemical formula . It is a white to slightly yellowish crystalline powder that is very soluble in water and is hygroscopic. From an industrial perspective, it is the most important nitrite sa ...

; the initial product spontaneously

tautomerize In chemistry, tautomers () are structural isomers (constitutional isomers) of chemical compounds that readily interconvert. The chemical reaction interconverting the two is called tautomerization. This conversion commonly results from the reloca ...

s to afford the

oxime In organic chemistry, an oxime is an organic compound belonging to the imines, with the general Chemical formula, formula , where R is an organic Side chain, side-chain and R' may be hydrogen, forming an aldoxime, or another organic functional g ...

(4). The bromoketone

functional group In organic chemistry, a functional group is any substituent or moiety (chemistry), moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions r ...

reacts with

thiourea Thiourea () is an organosulfur compound with the formula and the structure . It is structurally similar to urea (), with the oxygen atom replaced by sulfur atom (as implied by the '' thio-'' prefix). The properties of urea and thiourea differ s ...

in the penultimate step, forming the

thiazole Thiazole (), or 1,3-thiazole, is a 5-membered heterocyclic compound that contains both sulfur and nitrogen. The term 'thiazole' also refers to a large family of derivatives. Thiazole itself is a pale yellow liquid with a pyridine-like odor and the ...

ring of cefdinir, which is the product after removal of the

benzhydryl The benzhydryl compounds are a group of organic compounds whose parent structure, parent structural formula, structures include diphenylmethane (which is two benzene rings connected by a single substituent#Methane substituents, methane), with any ...

ester

protecting group A protecting group or protective group is introduced into a molecule by chemical modification of a functional group to obtain chemoselectivity in a subsequent chemical reaction. It plays an important role in multistep organic synthesis. In man ...

with

trifluoroacetic acid Trifluoroacetic acid (TFA) is a synthetic organofluorine compound with the chemical formula CF3CO2H. It belongs to the subclass of per- and polyfluoroalkyl substances (PFASs) known as ultrashort-chain perfluoroalkyl acids (PFAAs). TFA is not ...

Society and culture

Economics

Cefdinir was patented in 1979 and first approved for medical use in 1991. Warner-Lambert licensed the drug for marketing in the US from Fujisawa. Abbott later obtained U.S. marketing rights to cefdinir in December 1998 through an agreement with Warner-Lambert Company. It was approved by the

US FDA The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

on 4 December 1997. It is available in US as Omnicef by

Abbott Laboratories Abbott Laboratories is an American multinational medical devices and health care company with headquarters in Abbott Park, Illinois, in the United States. The company was founded by Chicago physician Wallace Calvin Abbott in 1888 to formulate k ...

and in India as Cednir by Abbott, Kefnir by Glenmark, Cefdair by Xalra Pharma and Cefdiel by

Ranbaxy Ranbaxy Laboratories Limited was an Indian multinational pharmaceutical company that was incorporated in India in 1961 and remained an entity until 2014. The company went public in 1973. Ownership of Ranbaxy changed twice over the course of its ...

. As of 2008, cefdinir was the highest-selling cephalosporin antibiotic in the United States, with more than $585 million in retail sales of its generic versions. In 2022, it was the 168th most commonly prescribed medication in the United States, with more than 3million prescriptions.

References

{{Portal bar , Medicine Wikipedia medicine articles ready to translate Thiazoles Drugs developed by AbbVie Astellas Pharma Vinyl compounds