SELECTION OF DRUGS FOR TREATMENT OF BACTERIAL AND FUNGAL INFECTIONS

By

Davis Mwakagile

Davis Mwakagile 204/08/23

Importance of rational choice of drugs

There is NO single antimicrobial drug that is effective against all causative agents

A microorganism that was sensitive to an antimicrobial drug sometime in the past may have become resistant to it

An antimicrobial drug that has been found to be effective in treating an infection caused by a certain microorganism may be so expensive that the patient cannot afford to buy it

Davis Mwakagile 304/08/23

Importance of rational choice of drugs -2 A particular antimicrobial drug may be so useful

in the treatment of one infection that it may not be wise to use it for treating other infections, for fear that its wide usage may lead to it being no longer effective in the treatment of the infection for which it is usually very good a good example is streptomycin that is reserved for

TB treatment only May not be available locally An antimicrobial drug that has been found to be

effective in treating an infection caused by a certain microorganism may cause allergic reaction(s) in the infected individual

Davis Mwakagile 404/08/23

BASIS FOR CHOOSING ANTIMICROBIAL DRUGS

Clinical impression Based on experience or “best guess” Usually provisional but may not be provisional

in health facilities without a lab support Changed after results from the lab

Clinicians tend to choose more than one antibiotic

Useful in treating life-threatening diseases before lab results are available

Davis Mwakagile 504/08/23

BASIS FOR CHOOSING ANTIMICROBIAL DRUGS -2

Bacteriological/fungal diagnosis Very important because in order for treatment

to be successful it must be aimed at the actual causative agent

The organism may be identified by microscopy alone or by both microscopy and culture

It also depends on past experience with the sensitivity pattern of the isolated causative agent

Or it may be based on the “best guess” on the sensitivity pattern of the organism

Davis Mwakagile 604/08/23

BASIS FOR CHOOSING ANTIMICROBIAL DRUGS -3

Sensitivity testing The mainstay of choosing an

antimicrobial drug for the treatment of bacteriological or fungal disease

It forms the basis of the practice of “evidence-based medicine” or scientific approach to choosing a drug

Sensitivity in the lab does not assure effective treatment

Davis Mwakagile 704/08/23

USE OF DRUGS IN COMBINATIONS Although the idea of using two or more drugs in

the treatment of microbial diseases sounds good, there may be problems

The combination of two or more drugs can cause three outcomes: Synergism: This is when the drugs in the

combination potentiate each other, i.e. the effect of each drug in the combination is greater than if it was used alone

Antagonism: The effect of one or both of the drugs in the combination is lower than if it was used alone

Indifference: The effect of each drug in the combination is not affected by the combination

Davis Mwakagile 804/08/23

Indications of using drugs in combination

In patients with life-threatening microbial diseases before laboratory diagnosis

however, it is essential to take a specimen before initiation of treatment

To deter the emergence of resistant strains to one drug in chronic infections requiring prolonged chemotherapy, e.g. in tuberculosis

To treat mixed infections whose causative agents are sensitive to different antimicrobial drugs

Patient Outcome

Nursing Intervention with Rationale

Evaluation

Patient will dress appropriately for age and status.

    Patient will eat and drink adequately to sustain fluid balance and  proper nutrition.

Offer assistance for selecting clothing and grooming to provide input and direction for appropriateness of dress and hygiene to preserve self-esteem and avoid embracement. Encourage and remind patient to drink fluid and to eat food to focus the patient on necessary feeding activities , to prevent dehydration and starvation.Provide recognition and positive reinforcement for feeding/dressing accomplishments to reinforce appropriate behaviours and enhance self-esteem.

Patient dresses self appropriately and maintains hygiene.

   Patient eats and drinks fluids necessarily to maintain physical health.

Davis Mwakagile 904/08/23

Indications of using drugs in combination -2

To reduce dosage of toxic antimicrobial drugs

To achieve synergism However, use of two or more drugs in

combination should be avoided as much as possible