The use of nonsteroidal anti inflammatory drugs

INTRODUCTION

These drugs are commmonally emphasized with the abbreviated name of “ NSAIDs ”.

Mainly shares the capacity to suppress the signs & symptoms of inflammation(Anti-inflammatory).

These  drugs also exert Anti-pyretic & Analgesic effect,But it is their anti-inflammatory properties that make them most useful in the management of disorders in which pain is related to intensity of the inflammatory processs.

Mechanism of action

Only one beautiful line , mentioned in the mother book of Pharmacology , explains the whole concept of mechanism;

INHIBITION OF PROSTAGLANDIN’S BIOSYNTHESIS

This inhibition is by inhibiting enzyme called ‘PROSTAGLADIN SYNTHASE’ or ‘CYCLOOXYGENASE’

Classification of NSAIDs

Non-selective COX inhibitors:-

 Asprin , ibuprofen , diclofenic , piroxicam.

Preferential COX-2 ihibitors:-

Meloxicam , nabumetone.

Selective COX-2 inhibitors:-

Celecoxib , parecoxib.

Analgesic antipyretic with poor anti-inflammatory action:-

Paracetamol

PHARMACOKINETICS

NSAIDs are rapidly & completely absorbed from GI tract.

Peak concentration occurs with in 1-4 hours.

The presence of food tends to delay the absorption without affecting peak concentration.

Most NSAIDs are extensively protein bound i.e. 95-99%.

PHARMACOKINETICS

NSAIDs undergo hepatic metabolism.

Renal excretion mechanism is involved for their elimination from body.

NSAIDs are not recommended in the setting of advanced hepatic & renal disease due their adverse pharmacodynamic effects.

DRUG INTERACTIONs

A drug interaction is a situation in which a substance affects the activity of a drug, i.e. the effects are increased or decreased, or they produce a new effect that neither produces on its own.

As we are talking about NSAIDs, the drug interaction may produce following general effects;

>>NSAIDs may antagonized the effect of other drug.

>>NSAIDs may be antagonized by the other drug to be administered.

           

DRUG INTERACTIONs

>>Plasma concentration of administered drug may increase or decrease under the influence of  NSAIDs.

>>Plasma concentration of  NSAIDs may increase or decrease  by  the administration of other drugs.

>>Toxicities may lead to renal & hepatic damage.

EXAMPLES OF DRUG INTERACTIONS

                 

EXAMPLES OF DRUG INTERACTIONS

EXAMPLES OF DRUG INTERACTIONS

EXAMPLES OF DRUG INTERACTIONS

 DRUG-FOOD INTERACTION

DRUG-DISEASE INTERACTION

Ulcer is potentiated by NSAIDs.

In Anti-cancer therapy the cytotoxic affect of the cytotoxic agents is increased. 

PATIENT CARE CONSIDERATION

Patient should be guided about possible side effects of drug and to follow the regimen according to prescriber.

The side effects may increase depending on the dose and frequency of NSAIDs.

Doctor may use higher doses of NSAIDs than “standard therapy”. Do not increase this dose without speaking with your doctor.

PATIENT CARE CONSIDERATION

PATIENT CARE CONSIDERATION

Prescriber may change to a different NSAIDs since one may work better than another for unclear reasons.

NSAIDs should be taken with food.

Do NOT combine NSAIDs without speaking with your pharmacist

For example, an arthritis patient taking daily Naproxen should NOT take another NSAID such as Ibuprofen if they develop a headache at the end of the day. Another type of medication, such as acetaminophen may be a better choice.

DURATION OF TREATMENT

The prescriber will decide the duration of treatment with NSAIDs.

Some condition require dosing 3-4 times a day for 2-3 days like anti pyretic action .

Some conditions require prolong use of NSAIDs like in gout treatment.

Patient condition and disease determine the duration of treatment.

Dosage of NSAIDs

Lower doses of NSAIDs are adequate to relieve pain in most people.

To fully treat inflammation, a higher dose of the NSAID must be taken on a regular basis for several weeks before the full anti inflammatory benefit is realized.

Dosage of NSAIDs

If the initial dose of NSAIDs does not improve symptoms, a clinician may recommend increasing the dose gradually or switching to another NSAID.

Dosage in renal impairment

Because most of the NSAIDs are excreted through the kidney.

NSAIDs may cause acute renal failure due to hypoperfusion and interstitial nephritis, as well as analgesic nephropathy (chronic interstitial nephritis and papillary necrosis).

Dose adjustment is necessary in patients with renal impairment

Some NSAIDs in combination are more nephrotoxic so avoiding these combinations can be life saving e.g aspirin and  paracetamol combinations.

Dosage in renal impairment

Dose recommendations are based on the severity of renal impairment. This is expressed in terms of glomerular filtration rate.

The serum creatinine concentration is sometimes used instead as a measure of renal function but is only a rough guide even when corrected for age, weight, and sex.

Nomograms should be used where accuracy is important.

Assessment and interventions

Assessment and intervention strategy is used in order to reduce the number of  (NSAIDs) users from possible side effects of  drug

Describe non-pharmacologic and pharmacologic self-care strategies for patients with musculoskeletal pain, headaches, and premenstrual and menstrual conditions.

Describe risk factors and management strategies for gastrointestinal toxicity induced by nonsteroidal anti-inflammatory drugs.

Assessment and interventions

 In the case of over-the-counter (OTC) drugs, pharmacist intervention mainly involved replacing NSAIDs for safer medications.

          ( e.g.  Replacing aspirin with safe alternative(alone responsible for 71% of GIT haemorrhages)

Pharmacist intervention involves selection of drug that is least toxic to patient e.g use of gastroprotective NSAIDs in patients with risk of gastric ulcer.

Discuss cautions and contraindications to the use of nonprescription analgesics.

Patient  family  education

patient family should be guided about possible side effects about NSAIDS