What is Antipyretics :-
- An Antipyretic drug is a substance that reduces fever. Antipyretics cause the hypothalamus to override a prostaglandin induced increase in temperature.
- The body then works to lower the temperature, which results in a reduction in fever.
- Most antipyretics have other purposes. The most common antipyretics in the United States are ibuprofen and aspirin, which are Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) used primarily as analgesics (pain relievers), but which also have antipyretic properties; and paracetamol (acetaminophen), an analgesic with weak anti-inflammatory properties.
Introduction :-
NSAIDs reduce body temperature in fever, but do not cause hypothermia in normo thermic individuals.
Fever during infection and tissue injury is produced through the generation of pyrogens including, IL, TNF, interferons which induce PGE, production in hypothalamus raise its temperature set point.
NSAIDs block the action of pyrogens but not that of PGE, injected into the hypothalamus.
Pharmacological Actions of Drugs :-
Aspirin =
- Analgesic, antipyretic, anti-inflammatory actions; Aspirin is a weaker analgesic (has lower maximal efficacy) than morphine.
Aspirin is used to reduce fever and relieve mild to moderate pain from conditions such as muscle aches, toothaches, common cold, and headaches. It may also be used to reduce pain and swelling in conditions such as arthritis.
Aspirin is known as a salicylate and a Nonsteroidal Anti-Inflammatory Drug (NSAID). It works by blocking a certain natural substance in your body to reduce pain and swelling.
#Consult your doctor before treating a child younger than 12 years.
PHARMACOKINETICS-
Aspirin is absorbed from the stomach and small intestines. Its poor water solubility is the limiting factor in absorption: microfining the drug-particles and inclusion of an alkali (solubility is more at higher pH) enhances absorption.
However, higher pH also favours ionization, thus decreasing the diffusible form.
ADVERSE EFFECTS-
(a) Side effects that occur at analgesic dose (0.3-1.5 g/day) are nausea, vomiting, epigastric distress, increased occult blood loss in stool. The most important adverse effect of aspirin is gastric mucosal damage and peptic ulceration.
(b) Hypersensitivity and idiosyncrasy Though infrequent, these can be serious. Reactions include rashes, fixed drug eruption, urticaria, rhinorrhoea, angioedema, asthma and anaphylactoid reaction.
Profuse gastric bleeding occurs in rare instances.
(c) Anti Inflammatory dose (3-5g/day) produce the syndrome called salicylism-dizzyness, tinnitus, vertigo, reversible impairment of hearing and vision, excitement and mental con fusion, hyperventilation and electrolyte imbalance.
Aspirin therapy in children with rheumatoid arthritis has been found to raise serum transami nases, indicating liver damage. Most cases are asymptomatic but it is potentially dangerous.
(d) Acute salicylate poisoning- It is more common in children. Fatal dose in adults is estimated to be 15-30 g, but is considerably lower in children. Serious toxicity is seen at serum salicylate levels > 50 mg/dl.
Manifestations are: Vomiting, dehydration, electrolyte imbalance, acidotic breathing, hyper/hypoglycemia, petechial hemorrhage, restlessness, delirium, hallucinations, hyperpyrexia, convulsions, coma and death due to respiratory failure + cardiovascular collapse.
USES-
- As analgesic; For headache (including mild migraine), backache, myalgia, joint pain, pulled muscle, toothache, neuralgia and dysmenorrhoea; it is effective in low doses (0.3-0.6 g, 6-8 hourly).
Analgesic effect is maximal at – 1000 mg (single dose).
- As antipyretic; Aspirin is effective in fever of any origin; dose is same as for analgesia.
However, paracetamol, being safer, is generally preferred. Antipyretics are not useful in fever due to heat stroke; only external cooling lowers body temperature.
- Acute rheumatic fever; Aspirin is the first drug to be used in all cases; other drugs are added or substituted only when it fails or in severe cases (corticosteroids act faster).
Granulomatous lesions, nodules, cardiac complications, valvular defects, chorea and duration of disease are not altered by salicylate therapy.
- Rheumatoid arthritis; Aspirin in a dose of 3-5 g/day is effective in most cases, produces relief of pain, swelling and morning stiffness, but progress of the disease process is not affected.
Since large doses of aspirin are poorly tolerated for long periods it is rarely used now; other NSAIDs are preferred.
- Osteoarthritis; It affords symptomatic relief only; may be used on ‘as and when required’ basis, but paracetamol is the first choice analgesic for most cases.
Ibuprofen =
It was the first member of this class to be introduced in 1969 as a better tolerated alternative to aspirin. Many others have followed. All have similar pharmacodynamic properties but differ considerably in potency and to some extent in duration of action.
Ibuprofen is used to relieve pain from various conditions such as headache, dental pain, menstrual cramps, muscle aches, or arthritis. It is also used to reduce fever and to relieve minor aches and pain due to the common cold or flu.
Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID). It works by blocking your body’s production of certain natural substances that cause inflammation. This effect helps to decrease swelling, pain, or fever.
SIDE EFFECTS-
Ibuprofen can increase your risk of fatal heart attack or stroke, especially if you use it long term or take high doses, or if you have heart disease.
#Do not use this medicine just before or after heart bypass surgery (coronary artery bypass graft, or CABG).
Ibuprofen may also cause stomach or intestinal bleeding, which can be fatal.
These conditions can occur without warning while you are using ibuprofen, especially in older adults.
Do not take more than your recommended dose. An ibuprofen overdose can damage your stomach or intestines. Use only the smallest amount of medication needed to get relief from your pain, swelling, or fever.
Naproxen =
It is available as both a generic and brand-name drug. Brand name:
Anaprox, Naprelan, and Naprosyn.
- There are two types of prescription naproxen: regular naproxen and naproxen sodium.
- All forms of prescription naproxen oral tablets help reduce swelling and pain. They are used to treat many conditions, including arthritis, menstrual pain, muscle and joint inflammation, and gout.
Naproxen oral tablets are used to treat pain and inflammation in a variety of conditions. It’s approved to treat:
- rheumatoid arthritis
- osteoarthritis
- ankylosing spondylitis
- juvenile arthritis
- menstrual period pain
- tendonitis
- bursitis
- symptoms of gout
Other Antipyretics :-
Ketoprofen
It is used to relieve pain from various conditions. It also reduces pain, swelling, and joint stiffness from arthritis.
This medication is a nonsteroidal anti- inflammatory drug (NSAID) or antipyretics. It works by blocking your body’s production certain natural substances that cause inflammation. This effect helps to decrease swelling, pain, or fever.
Flubiprofen
It is used to reduce pain, swelling, and joint stiffness from arthritis.
This medication is known as a nonsteroidal anti-inflammatory drug (NSAID).
Mefenamic acid
It is used for the short-term treatment of mild to moderate pain from various conditions. It is also used to decrease pain and blood loss from menstrual periods.
Mefenamic acid oral capsule is available as a generic drug and a brand-name drug. Brand name:
Ponstel.
- Mefenamic acid only comes as a capsule you take by mouth.
- Mefenamic acid oral capsule is used to treat mild to moderate pain and dysmenorrhea (menstrual pain).
What is mefenamic acid?
Mefenamic acid is a prescription drug. It only comes as an oral capsule. It is used to treat mild to moderate pain and dysmenorrhoea (menstrual cramps).
It’s approved to treat pain in people who are least 14 years old for no longer than seven days. It’s approved to treat menstrual cramps for no longer than two to three days.
Piroxicam
It is used to reduce pain, swelling, and joint stiffness from arthritis. Reducing these symptoms helps you do more of your normal daily activities.
This medication is known as a nonsteroidal anti-inflammatory drug (NSAID). It works by blocking your body’s production of certain natural substances that cause inflammation.
Tenoxicam
It is sold under the brand name Mobiflex among others, is a (NSAID).
It is used to relieve inflammation, swelling, stiffness, and pain associated with rheumatoid arthritis, osteoarthritis, ankylosing spondylitis (a type of arthritis involving the spine), tendinitis (inflammation of a tendon), bursitis (inflammation of a bursa, a fluid-filled sac located around joints and near the bones), and periarthritis of the shoulder or hips (inflammation of tissues surrounding these joints).
Ketorolac
It is used for the short-term treatment of moderate to severe pain in adults. It is usually used before or after medical procedures or after surgery.
Reducing pain helps you recover more comfortably so that you can return to your normal daily activities. It is NSAIDs or antipyretics. It works by blocking your body’s production of certain natural substances that cause inflammation. This effect helps to decrease swelling, pain, or fever.
Indometacin
Also known as indomethacin, is a (NSAID) commonly used as a prescription medication to reduce fever, pain, stiffness, and swelling from inflammation.
It works by inhibiting the production of prostaglandins, endogenous signaling molecules known to cause these symptoms. It does this by inhibiting cyclooxygenase, an enzyme that catalyzes the production of prostaglandin.
Nabumetone
It is a nonsteroidal anti inflammatory drug (NSAID). It is available under numerous brand names, such as Relafen, Relifex, and Gambaran.
Nabumetone has little effect on renal prostaglandin secretion and less of an association with heart failure than other traditional drugs of the class.Effects of nabumetone on blood pressure control in hypertensive patients on ACE inhibitors is also good-equivalent to paracetamol.
Metamizole
or dipyrone, is a painkiller, spasm reliever, and fever reliever that also has anti- inflammatory effects. It is most commonly given by mouth or by injection.
Nimesulide
It is a nonsteroidal anti- inflammatory drug (NSAID) with pain medication and fever reducing properties. Its approved indications are the treatment of acute pain, the symptomatic treatment of osteoarthritis, and primary dysmenorrhoea in adolescents and adults above 12 years old.
Side effects may include liver problems. It has a multifactorial mode of action and is characterized by a fast onset of action. It works by blocking the production of prostaglandins (a chemical associated with pain), thereby relieving pain and inflammation.
