In the WMF, individual drug monographs are closely associated with the introductory information for each section and the information in the appendices (Figure 4.1).
Figure 4.1. Interconnected structure of the WHO model formulary
This structure means that certain facts about an individual drug do not always appear in the relevant monograph: instead cross-reference is made to the introductory text of the section or other sections, and to the appendices.
This can make transferring single monographs or chapters into the NF complicated. Because of this existing structure, there are two main ways in which passages from the WMF may be adapted for inclusion in a NF:
Option 1. Keep the full text of the WMF and make additions by inserting the text of national recommendations and drug information in the relevant places and use limited deletions in “blocks” to remove irrelevant WMF information.
Option 2. Very thoroughly edit (cut and paste, delete and modify) all types of entries, including the appendices.
If the first option is used, the full text of the WMF is reproduced without alteration or with minimal changes. National recommendations and important information on local medicines are inserted in a consistent manner in the appropriate places into the copy of the WMF text. This can best be achieved by using a uniform formatting style, i.e. a different font and type-size to distinguish the additional NF information from the WMF content and to alert the reader to the national information. Other formatting techniques, i.e. the use of bold text, underlining and italics should be avoided except in the contexts in which they are used in the WMF. An example of the insertion of national information is shown in Figure 4.2.
Deletions should be made very cautiously, preferably in “blocks”, i.e. if it is not intended to keep the section on Leprosy, then the complete subsection of “6.2.3. Antileprosy drugs” may be deleted, or monographs on irrelevant drugs deleted in full. Care should be taken to ensure that the remaining sections do not contain cross-references to the one that has been deleted.
If the NF list is very comprehensive, extensive additions to the monograph sections may be necessary. Since many of these additions will be “me-too” medicines (i.e. belonging to the same pharmacological class and having similar efficacy and safety), the introductory text of the WMF could remain relevant and can promote rational choices. For the writing of new monographs it is essential to use authoritative drug information resources (see Chapter 5) and very careful editing (see notes on copy-editing below).
The use of this first option can be relatively straightforward for those countries where either there is no national EML and treatment guidelines, or there is a good overlap between the WMLEM and the national EML and it is possible to maintain the same or a very similar classification.
Figure 4.2. Example of addition of national information to WHO model formulary text
Various regimens have been used to specifically prevent the transmission of HIV from mother to the neonate at term. More information is available in New Data on the Prevention of Mother-to-Child Transmission of HIV and their Policy Implications: Conclusions and Recommendations (WHO/RHR/01.28), which reflects an inter-agency consultation held on 11-13 October 2000.
Tablets, nevirapine 200 mg
Oral suspension, nevirapine 50 mg/5 ml
Uses: HIV infection, in combination with at least two other antiretroviral drugs; prevention of mother-to-child transmission in HIV-infected patients (but see notes above under Pregnancy)
In Zimbabwe the risk of mother to child transmission of HIV is high. Based on seroprevalence data collected in 2001 and the estimated 15-45% transmission rate, approximately 50 000 infants get infected annually. The simple nevirapine regimen is recommended for prevention as outlined in the Prevention of Mother to Child transmission of HIV (PMTCT) - National site protocols for Ministry of Health & Child Welfare, Edition 1 February 2003. It is important to integrate the administration of nevirapine in a comprehensive care package including essential interventions such as counselling and voluntary testing of pregnant women, safe obstetrical practices and infant feeding education. Nevirapine is freely available at public health care facilities enrolled in PMTCT programmes (more than 160 sites with 120 rural health centres included as of July 2003). For more details contact the National AIDS & TB Unit in MOH&CW.
hepatic impairment (see below and Appendix 5); renal impairment; pregnancy (see notes above); breastfeeding (see notes above);
interactions: Appendix 1
Potentially life-threatening hepatotoxicity including fatal fulminant hepatitis reported usually occurring in first 8 weeks; monitor liver function before long-term treatment then every 2 weeks for 2 months then after 1 month and then every 3-6 months; discontinue permanently if abnormalities in liver function tests accompanied by hypersensitivity reaction (rash, fever, arthralgia, myalgia, lymphadenopathy, hepatitis, renal impairment, eosinophilia, granulocytopenia); suspend if severe abnormalities in liver function tests but no hypersensitivity reaction; discontinue permanently if significant liver function abnormalities recur; monitor patient closely if mild to moderate abnormalities in liver function tests with no hypersensitivity reaction
Rash, usually in first 8 weeks, is most common adverse effect; incidence reduced if introduced at low dose and dose increased gradually; discontinue permanently if severe rash or if rash accompanied by blistering, oral lesions, conjunctivitis, swelling, general malaise or hypersensitivity reactions; if rash mild or moderate may continue without interruption but dose should not be increased until rash resolves
Patients should be told how to recognize hypersensitivity reactions and advised to seek immediate medical attention if symptoms develop
HIV infection (in combination with other antiretroviral drugs), by mouth, ADULT 200 mg once daily for first 14 days then (if no rash present) 200 mg twice daily; INFANT 15-30 days old, 5 mg/kg once daily for 14 days, then (if no rash present) 120 mg/m2 twice daily for 14 days, then 200 mg/m2 twice daily; CHILD 1 month-13 years, 120 mg/m2 twice daily for first 14 days, then (if no rash present) 200 mg/m2 twice daily
Prevention of mother-to-child transmission of HIV (see also notes above under Pregnancy), by mouth, ADULT 200 mg as a single dose at onset of labour; NEONATE 2 mg/kg as a single dose within 72 hours of birth
If treatment interrupted for more than 7 days reintroduce with 200 mg daily (INFANT 15-30 days old, 5 mg/kg; CHILD over 1 month, 120 mg/m2) and increase dose cautiously
NEVIRAPINE for PMTCT in Zimbabwe:
• One 200 mg dose by mouth to HIV positive mother at onset of labour (aim for early administration so mother delivers 24-48 hours after taking the nevirapine)
• SOME HIV exposed babies will receive a 0.6 ml or 6 mg dose of nevirapine suspension by mouth immediately after delivery (under special circumstances e.g. speedy delivery, mother did not take NVP prior to delivery)
• ALL HIV exposed babies will receive one 0.6 ml or 6 mg dose of suspension 48-72 hours after delivery (this includes babies who have already been given a dose immediately after birth).
Note: For information on procedures to be followed for women in labour with unknown HIV status and other details, see the national protocol mentioned above.
Adverse effects: rash including Stevens-Johnson syndrome and rarely, toxic epidermal necrolysis (see also Precautions above); hepatitis or jaundice reported (see also Precautions above); nausea, vomiting, abdominal pain, diarrhoea, headache, drowsiness, fatigue, fever; hypersensitivity reactions (may involve hepatic reactions and rash, see Precautions above); anaphylaxis, angioedema, urticaria also reported
Brand names: Viramune 200mg tablets and 50 mg/5ml suspension (Ingelheim Pharmaceuticals), Nevimune 200mg tablets (CIPLA Pvt. Ltd.) Nevipane 200 mg tablets (Ranbaxy Pvt Ltd),
Price: Viramune 200mg 60 tabl. Z$ IIIIII, 50mg. 5ml 240ml suspension; Nevimune 200mg 60 tablets Z$ CCCC, Nevipane 200 mg 60 tablets, Z$ RRRR
The second option might be necessary when the NF list (the classification system used and medicines included) and the national recommendations are different from those in the WMF. The rearrangement of sections and re-editing of clinical information to match recommendations to local protocols will be unavoidable in those countries where an EML and national standard treatment guidelines already exist and are widely used. Although the monographs themselves may need little change, extensive work will be required to correct the cross-references.
Extensive changes to the WMF will require highly skilled editorial input, complex rearrangements and the addition of substantial amounts of new text. As such extensive re-editing can easily introduce new errors and unwanted artefacts, it will be crucial to validate the draft text, using up-to-date and suitable drug information resources (see Chapter 5). The adoption of the second option will require considerably more time and resources than the first option.