Fungal Infection

Question 1

Aspergillosis (fungi affect the tissues… commonly the lungs)

Answer 1

• Voriconazole is the treatment of choice, alternatively give Liposomal Amphotericin
• Caspofungin or Itraconazole can be used if patients are refractory/intolerant to the above drugs
• 3rd line… Posaconazole can be used for patients refractory/intolerant of itraconazole/amphotericin.

Question 2

Candidiasis

Answer 2

 Vaginal candidiasis may be treated with Clotrimazole or with Fluconazole (given by mouth) and for resistant organisms… itraconazole can be given orally.
 Oral candidiasis generally responds to Miconazole, fluconazole is given orally for unresponsive infections. It is effective and reliably absorbed. Itraconazole is given for infections that do not respond to fluconazole.

Question 3

Skin and nail infections

Answer 3

 Tinea Capitis (ringworm of the hair) is treated systemically with Griseofulvin (adults and children) or Terbinafine (unlicensed)
 Pityriasis versicolor (causes patches of skin to become scaly/discoloured) is treated with Itraconazole orally if topical therapy is ineffective. Fluconazole by mouth is an alternative.
 Onychomycosis (fungal nail infection) is treated with oral terbinafine (1st line) or itraconazole.

Question 4

Triazole antifungals

Answer 4

• Fluconazole is very well absorbed after oral administration and is excreted largely unchanged in the urine. Discontinue if rash develops
• It is taken ONCE daily but should not be used in pregnancy. It may interact with statins, warfarin, diazepam, phenytoin and theophylline (all effects are increased).
• Itraconazole capsules require an acid environment in the stomach for optimal absorption.
• Itraconazole has been associated with liver damage and should be avoided or used with caution in patients with liver disease and heart failure. Fluconazole is less frequently associated with hepatotoxicity.

Question 5

Imidazole antifungals

Answer 5

The imidazole antifungals include clotrimazole and ketoconazole which are used for vaginal candidiasis.
- Miconazole can be used locally for oral infections, it is also effective in intestinal infections. Systemic absorption may follow use of miconazole oral gel and may result in significant drug interactions.

Question 6

Polyene antifungals

Answer 6

The polyene antifungals include Amphotericin and Nystatin, neither drug is absorbed when given by mouth.
 Nystatin is used for oral infections by local application in the mouth e.g. oral thrush.
 Amphotericin by I.V. infusion is used for the treatment of systemic fungal infections + is active against most fungi and yeasts.
 When given parenterally amphotericin is toxic and side-effects are common. Lipid formulations (e.g. Abelcet and AmBisome) are significantly less toxic and better, but more expensive.
 Amphotericin should be prescribed by BRAND NAME since formulations are not interchangeable.
To use amphotericin, a test-dose must first be given. Patients should be monitored with LFTs, eGFR, FBC and electrolytes.

Question 7

Co-Trimoxazole, Important safety information

Answer 7

It should only be considered for use in acute exacerbations of bronchitis and in UTIs when there is bacteriological evidence of sensitivity to this drug

Question 8

Pneumocystis pneumonia

Answer 8

Pneumonia caused by the Pneumocystis jirovecii occurs in immunosuppressed patients and is a common cause of pneumonia in AIDS.

Question 9

Pneumocystis pneumonia - Mild to moderate disease

Answer 9

• Co-trimoxazole in high dosage is the drug of choice for mild-moderate pneumocystis pneumonia.
• If patients cannot tolerate co-trimoxazole then Atovaquone is given

Question 10

Pneumocystis pneumonia - Severe disease

Answer 10

• Co-trimoxazole in high dosage by mouth or I.V. infusion is the drug of choice for severe pneumocystis pneumonia.
• If cannot above then Pentamidine isetionate is given by I.V. infusion. However, it is potentially toxic, and can cause severe hypotension during or immediately after infusion. Corticosteroids can be lifesaving.

Question 11

Pneumocystis pneumonia - Adjunctive therapy

Answer 11

• In moderate to severe infections associated with HIV infection, Prednisolone is given by mouth for 5 days… alternatively parenteral Hydrocortisone can be given
• The dose is then reduced to complete 21 days of treatment. Corticosteroid treatment should ideally be given at the same time as anti-pneumocystis therapy (no later than 24-72h afterwards) + should be withdrawn before anti-pneumocystis therapy is complete.

Question 12

Pneumocystis pneumonia - Prophylaxis

Answer 12

• Co-trimoxazole by mouth is given daily or on alternate days (3 times a week). If patients cannot tolerate this then give intermittent inhaled Pentamidine Isetionate. Alternatively dapsone or atovaquone.