Pink eye may sound terrifying but it is a common and treatable eye condition. As per recent estimate by National Eye Institute, about 3 million cases of pink eye are reported each year in the US.[1]
Medically, it is known as conjunctivitis, and refers to an inflammation of the conjunctiva. Conjunctiva is a clear, thin membrane covering the front surface of the eye and lines the inner surface of the eyelids. This inflammatory response is evoked by infection (bacteria or virus), allergy or exposure to irritants. Bacterial and viral conjunctivitis are highly contagious, i.e. they tend to spread through contact with an infected person.
Although conjunctivitis produces some distressing symptoms, it is not a life-threatening condition and it does not affect the vision.
Symptoms
Irritation and inflammation of the conjunctiva may present as following symptoms, in one or both eyes.
- A gritty sensation in the eye, i.e. a feeling that something is stuck in the eye
- Redness of the eye
- Pain, itching and burning sensation in the eye
- Thick pus discharge from eyes that sticks to the eyelashes
- Watery eyes
- Increased sensitivity to light (medically termed as photophobia)
Treatment
The treatment of conjunctivitis varies, depending on the type of conjunctivitis. The goal of treatment is to provide symptomatic relief, shorten the course of the disease and cause eradication of infection (if any).
Conjunctivitis usually runs its own course without any need for medication. However, presence of a bacterial infection or severe symptoms may require drug therapy. Most of the medications used in conjunctivitis are topical ointments or eye drops.
Bacterial conjunctivitis necessitates treatment by antibiotics, either as eye drops or ointments. However, oral and injectable antibiotics may be required to treat conjunctivitis caused by chlamydia or gonorrhea infection. Allergic conjunctivitis is usually treated by ophthalmic preparations of antihistamines, mast cell stabilizers, decongestants, non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids (in severe cases). Viral conjunctivitis is self-limiting and resolves on its own. However, topical antihistamines and decongestants may help relieve the symptoms in viral conjunctivitis.
Drugs for Bacterial Conjunctivitis
Antibiotic ophthalmic formulations are used to treat bacterial conjunctivitis. The antibiotics used are described below.
Antibiotics
Antibiotics, also known as antibacterial drugs are used in the prevention and treatment of bacterial infection. Consulting an eye doctor to confirm the presence of bacterial conjunctivitis is important as antibiotics are strictly contraindicated in viral and allergic conjunctivitis.
Topical antibiotics are preferred over oral and injectable preparations in the treatment of conjunctivitis.
1. Fluoroquinolones
This group of drugs inhibits bacterial enzymes, namely DNA gyrase and Topoisomerase IV, which are essential for bacterial DNA synthesis. Hampered DNA synthesis kills the bacteria. Hence, fluoroquinolones produce a bactericidal effect.
I. Ist-generation fluoroquinolones
These constitute the earlier developed fluoroquinolones and are used for mild bacterial conjunctivitis.
Available as: Ophthalmic preparations (solution/ eye drops)
A. Norfloxacin
US-FDA Status: Unapproved for Conjunctivitis
Availability: Discontinued
Generic name: norfloxacin
Brand name: Chibroxin solution/ eye drop
Side-effects: Burning or discomfort in eye, photophobia
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
B. Ofloxacin
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: ofloxacin
Brand name: Ocuflox solution/ eye drop
Side-effects: Puffiness of eyes, hives, itching, rash
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
C. Ciprofloxacin
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: ciprofloxacin
Brand name: Ciloxan solution/ eye drop
Side-effects: Eye discomfort, corneal deposits, irritation or redness of eye
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
II. IInd generation fluoroquinolones
These are newly developed fluoroquinolones and are reserved for severe bacterial conjunctivitis.
Available as: Ophthalmic preparations (solution/ eye drops)
A. Levofloxacin
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: levofloxacin
Brand name: Levofloxacin solution/ eye drop
Side-effects: Congestion, sore throat, runny nose,
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
B. Moxifloxacin
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: moxifloxacin hydrochloride
Brand name: Moxeza solution/ eye drop
Side-effects: Itching, skin rash, fainting
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
2. Aminoglycosides
Aminoglycosides block the initiation of protein synthesis and alters the bacterial cell membrane, thus killing the bacteria and producing a bactericidal effect.
Available as: Ophthalmic preparations (solution/ eye drops)
I. Gentamicin
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: gentamicin sulfate
Brand name: Gentak solution/ eye drop
Side-effects: Redness, itching, swelling of eye, blurred vision
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
II. Tobramycin
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: tobramycin
Brand name: AK-Tob solution/ eye drop
Side-effects: Redness, itching, swelling of eye, watery eyes
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
3. Macrolides
Macrolides bind to a specific ribosomal unit of bacteria, thus inhibiting protein synthesis. Hence, macrolides prevent the growth of bacteria, producing bacteriostatic effect.
I. Erythromycin
Available as: Oral preparations and Ophthalmic preparations (ointment)
Ophthalmic Erythromycin
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: erythromycin
Brand name: Erythromycin ointment
Side-effects: Eye irritation, redness and swelling of eye
Indicated in pregnancy: Can be safely used in pregnancy
Alcohol content: Absent
Oral Erythromycin
These are indicated in neonatal conjunctivitis caused by chlamydial infection.
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: eryhtromycin
Brand name: Ery-tab tablet
Side-effects: Diarrhea, chills, cough, dizziness, fast heartbeat
Indicated in pregnancy: Usually indicated
Alcohol content: Absent
II. Azithromycin
Available as: Oral preparations and Ophthalmic preparations (solution/ eye drops)
Ophthalmic Azithromycin
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: azithromycin
Brand name: AzaSite solution/ eye drop
Side-effects: Redness, burning or irritation of eye, cough, blurred vision
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
Oral Azithromycin
It is used for the treatment of chlamydial conjunctivits along with genitourinary chlamydial infection. It is also used to treat gonorrhea-induced conjunctivitis.
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: azithromycin
Brand name: Zithromax oral suspension
Side-effects: Loose stools, diarrhea, fever, cracked skin
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
4. Tetracycline Group of Drug
This group pf drug inhibits the bacterial protein synthesis by binding to a particular ribosome. It is a bacteriostatic agent.
I. Doxycycline
It is used to treat adult conjunctivitis caused by chlamydial infection.
Available as: Oral preparations
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: doxycycline hyclate
Brand name: Doryx capsule
Side-effects: Bloating, constipation, chills, clay colored stools, cough, dark urine
Indicated in pregnancy: Usually contraindicated, but can be given if benefit outweighs fetal risk
Alcohol content: Absent
5. Beta-lactam antibiotics
This group of drug kills the bacteria by inhibiting the bacterial cell wall synthesis. Hence, they have a bactericidal effect.
I. Third-generation cephalosporins
A. Ceftriaxone
It is used intramuscularly or intravenously in the treatment of adult gonococcal conjunctivitis.
Available as: Injectable preparations (intravenous and intramuscular)
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: cerftriaxone sodium
Brand name: Ceftriaxone injection
Side-effects: Swelling, pain or redness at the injection site
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
II. Penicillin
Intravenous Penicillin G is used in the treatment of neonatal gonorrhea.
Available as: Oral preparations and Injectable preparations (intramuscular and intravenous)
A. Penicillin G
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: penicillin g potassium
Brand name: Pfizerpen injection
Side-effects: Rash, hives, dizziness, headache
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
6. Polypeptide antibiotics
This group of antibiotic kills the bacteria by inhibiting its cell wall synthesis.
I. Bacitracin
Available as: Ophthalmic preparation, usually ointment.
US-FDA Status: Unapproved for Conjunctivitis
Availability: Discontinued
Generic name: bacitracin
Brand name: Bacitracin ophthalmic ointment
Side-effects: Hives, itching, peeling of skin, fever, wheezing
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
7. Combination of Polypeptide antibiotic and Diaminopyrimidines
As already stated polypeptide antibiotics produce a bactericidal effect. Diaminopyrimidine is a bacteriostatic group of drug, which inhibits the formation of folic acid in bacteria. Folic acid is an important constituent required for all metabolic reactions of bacteria. Thus, diaminopyrimidines inhibit the bacterial growth.
This combination of bacteriostatic and bactericidal drug is effective in counteracting conjunctivitis.
Available as: Eye drops
I. Polymyxin B Sulfate and Trimethoprim
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: polymyxin B sulfate/ trimethoprim
Brand name: Polytrim eye drop
Side-effects: Change in eyesight, eye pain or irritation, hives, itching
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
8. Gramicidin
Gramicidin or Gramicidin D is a combination of three antibiotic compounds, gramicidins A, B and C. It alters the cell membrane of the bacteria, thus killing the bacteria and producing a bactericidal effect.
Available as: Ophthalmic preparations (eye drops/ solutions) , in combination with neomycin sulfate and polymyxin B sulfate
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: gramicidin/ plymyxin B sulfate/ neomycin sulfate
Brand name: Neosporin solutions/ eye drops
Side-effects: Redness, itching, rash, swelling in or around the eye
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
An interesting fact here is that Neosporin ophthalmic ointment differs from neosporin ophthalmic solution in it’s composition. The ophthalmic ointment lacks gramicidin and consists of a combination of bacitracin, polymyxin B sulfate and neomycin sulfate. However, both the preparations are effective in the treatment of bacterial conjunctivitis.
9. Sulfonamides
This group of drug is a bacteriostatic agent. It inhibits a bacterial chemical, known as para aminobenzoic acid (PABA). This chemical is necessary to form folic acid, which in turn stimulates the growth of bacteria. By inhibiting PABA, sulfonamides inhibit the bacterial growth, thus producing a desirable result in bacterial conjunctivitis.
Sulfacetamide sodium is the only sulfonamide antibiotic, used in the treatment of conjunctivitis.
I. Sulfacetamide sodium
Available as: Opthalmic preparations (solutions/ eye drops)
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: sulfacetamide sodium
Brand name: Bleph-10 solutions/ eye drops
Side-effects: Stinging, burning or irritation of eye
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
Drugs for Allergic Conjunctivitis
The American Academy of Allergy, Asthma and Immunology lists down various class of drugs to ameliorate the symptoms of allergic conjunctivitis.[1] These drugs are enlisted below.
1. H1 Receptor Antagonists
Four types of histaminergic receptors have been identified, namely H1, H2, H3 and H4. Histamine is a protein molecule stored in mast cells. When an allergen enters a body, mast cells release histamines which act on histaminergic receptors and an allergic reaction is elicited. H1 receptor antagonists block the H1 receptors, thus the action of histamine is inhibited and allergic symptoms such as itching in the eye is relieved.
Available as: Ophthalmic preparations (solution/ eye drops)
I. Alcaftadine
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: alcaftadine
Brand name: Lastacaft eye drops
Side-effects: Hives, itching, red sore eyes
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
II. Bepotastine besilate
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: bepotastine besilate
Brand name: Bepreve solution/ eye drop
Side-effects: Hives, difficulty breathing, eye irritation, headache
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
III. Emadastine
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: emadastine difumarate
Brand name: Emadine eye drop/ solution
Side-effects: Blurred vision, eye irritation, eye redness
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
IV. Olapatidine
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: olapatidine hydrochloride
Brand name: Patanol solution/ drops
Side-effects: Swelling of eyelids, eye irritation, blurred vision
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
V. Azelastine
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: azelastine hydrochloride
Brand name: Azelastine Hydrochloride
Side-effects: Cough, shortness of breath, chest tightness, wheezing
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
Azelastine is also used as a nasal spray in the treatment of hay fever.
2. Mast Cell Stabilizers
This group of drug stabilizes the mast cells, thus inhibiting the release of histamine, which produces allergic symptoms. Hence, mast cell stabilizers are used in allergic conjunctivitis to relieve the symptoms.
Available as: Ophthalmic preparations (usually eye drops)
I. Cromoglicic acid
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: cromolyn sodium
Brand name: Crolom solution/drops
Side-effects: Redness or rash around eyes, eye irritation, burning or stinging of eye
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
II. Ketotifen
US-FDA Status: Approved for Conjunctivitis
Availability: Over the counter
Generic name: ketotifen fumarate
Brand name: Alaway solution/ eye drops
Side-effects: Eyelid swelling, redness, changes in vision, itching of eyes
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
III. Lodoxamide
US-FDA Status: Approved for Conjunctivitis
Availability: Over the counter
Generic name: lodoxamide tromethamine
Brand name: Alomide solution/ eye drops
Side-effects: Blurred vision, eye irritation, eye itching, dry eyes
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
IV. Nedocromil
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: nedocromil sodium
Brand name: Alocril solution/ eye drops
Side-effects: Cough, change in vision, blurred vision, dry itchy eyes, headache, chest tightness, shortness of breath
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Absent
V. Pemirolast
US-FDA Status: Unapproved for Conjunctivitis
Availability: Discontinued
Generic name: pemirolast potassium
Brand name: Alamast solution/ eye drops
Side-effects: Abdominal pain, headache, cough, runny nose, chest tightness
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
Cromolyn sodium is also available as a nasal spray for the treatment of allergic rhinitis.
3. Non-Steroidal Anti-inflammatory Drugs (NSAIDs)
This group of drug inhibits cyclo-oxygenase enzyme and prevents the release of inflammatory mediator, called Prostaglandins. Hence, NSAIDs relieve the conjunctival inflammation and hasten the recovery, particularly in allergic conjunctivitis.
I. Acetic acid derivatives
Ketorolac is the only approved NSAID for the treatment of itchy eyes.
Available as: Opthalmic preparations (solution/ eye drops)
A. Ketorolac
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: ketorolac tromethamine
Brand name: Acular
Side-effects: Redness, itching or irritation of eye, sensiitivity to light, eye swelling, throbbing pain
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
4. Decongestants
These belong to a class of drug, known as “Alpha adrenergic agonist”. This group of drugs stimulates the alpha-adrenergic receptors of the eye and relieves congestion by constricting the blood vessels, thus reducing inflammation and redness seen in allergic conjunctivitis.
Available as: A combination of decongestants are being sold as ophthalmic preparations (Eye drops/ solution).
I. Naphazoline and Pheniramine
US-FDA Status: Approved for Conjunctivitis
Availability: Over the counter
Generic name: naphazoline hydrochloride/ pheniramine maleate
Brand name: Naphcon-A
Side-effects: Rash, hives, wheezing, eye pain, change in eyesight
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
5. Corticosteroids
Corticosteroids are a group of steroid hormones, which are normally released by the adrenal glands. These are potent anti-inflammatory drugs and relieve the conjunctival inflammation, thus hastening the recovery.
Available as: Ophthalmic preparations (solution/ suspension/ eye drops)
I. Loteprednol
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: loteprednol etabonate
Brand name: Alrex solution/ eye drop
Side-effects: Blurred vision, swelling or redness of eye, changes in vision, sensitivity to light, discharge from eye
Indicated in pregnancy: Only if absolutely indicated
Alcohol content: Absent
II. Dexamethasone
US-FDA Status: Approved for Conjunctivitis
Availability: Prescription only
Generic name: dexamethasone
Brand name: Maxidex suspension/ eye drop
Side-effects: Bloody eye, change in vision, eye pain, blurred vision, loss of vision, headache
Indicated in pregnancy: Only if benefit outweighs fetal risk
Alcohol content: Contains traces of alcohol (0.25% as phenylethyl alcohol in preservative)
As already mentioned, drug therapy is not recommended for viral conjunctivitis.
OTC
There are various over the counter medications available for the treatment of conjunctivitis. These include antibiotics and anti-allergics, which are readily available as over the counter eye drops or ointments. Oral antibiotics, such as azithromycin may also be available as an OTC in some countries.
The availability of these medications vary from country to country, depending on the norms of the respective drug regulatory body. Various OTC drugs for conjunctivitis available in different countries have been enlisted in the table below.
| Name of the Country | OTC Drug(s) Available |
| Argentina | Sulfacetamide sodium (ophthalmic preparations) |
| Australia | Cromoglicic acid (ophthalmic preparations) Ketotifen (ophthalmic preparations) Sulfacetamide (ophthalmic preparations) |
| Austria | Cromoglicic acid (ophthalmic preparations) Naphazoline (ophthalmic preparations) |
| Canada | Polymyxin B (ophthalmic preparations) Cromoglicic acid (ophthalmic preparations) |
| China | Erythromycin (ophthalmic ointment) Levofloxacin (ophthalmic preparations) Sulfacetamide sodium (ophthalmic preparations) |
| Denmark | Lodoxamide (ophthalmic preparations) Naphazoline (ophthalmic preparations) Ketotifen (ophthalmic preparations) |
| France | Cromoglicic acid (ophthalmic preparations) Lodoxamide (ophthalmic preparations) |
| Germany | Lodoxamide (ophthalmic preparations) Cromoglicic acid (ophthalmic preparations) |
| Hungary | Azelastine (ophthalmic preparations) Cromoglicic acid (ophthalmic preparations) |
| India | Polymyxin B (ophthalmic preparations) Tetrahydrozoline (ophthalmic preparations) |
| Ireland | Naphazoline (ophthalmic preparations) |
| Italy | Polymyxin B (ophthalmic preparations) Sulfacetamide sodium (ophthalmic preparations) |
| Japan | Polymyxin B (ophthalmic preparations) Cromoglicic acid (ophthalmic preparations) Ketotifen (ophthalmic preparations) |
| Mexico | Polymyxin B (ophthalmic preparations) Sulfacetamide sodium (ophthalmic preparations) |
| Philippines | Polymyxin B (ophthalmic preparations; but only in combination) |
| Russia | Gentamicin (ophthalmic preparations) Dexamethasone (ophthalmic preparations) Gramicidin (ophthalmic preparations) Sulfacetamide sodium (ophthalmic preparations) |
| South Korea | Polymyxin B (ophthalmic preparations) Sulfacetamide sodium (ophthalmic preparations) |
| Spain | Polymyxin B (ophthalmic preparations) Azelastine (ophthalmic preparations) Cromoglicic acid (ophthalmic preparations) Naphazoline (ophthalmic preparations) Tetrahydrozoline (ophthalmic preparations) |
| UK | Azithromycin (oral) Azelastine (ophthalmic preparations) Cromoglicic acid (ophthalmic preparations) Lodoxamide (ophthalmic preparations) Naphazoline (ophthalmic preparations) |
| USA | Polymyxin B (ophthalmic preparations) Ketotifen (ophthalmic preparations) Lodoxamide (ophthalmic preparations) Naphazoline (ophthalmic preparations) |
Although conventional medications combined with various at-home measures can effectively manage the condition, care must also be taken to prevent the spread of infection to others.
Lastly, doctors strictly condemn self-medication in conjunctivitis and an eye doctor’s consultation must be sought to effectively combat the condition.
