| E.1 Medical condition or disease under investigation | 
| E.1.1 | Medical condition(s) being investigated |  | 
| MedDRA Classification | 
| E.1.3 | Condition being studied is a rare disease | No | 
| E.2 Objective of the trial | 
| E.2.1 | Main objective of the trial | 
| To compare the nevirapine trough plasma levels after 7 days of initial full dose nevirapine treatment or following the dose escalation treatment in patients taking efavirenz and switching to nevirapine due to neuropsychiatric adverse reactions. |  | 
| E.2.2 | Secondary objectives of the trial | 
| -To measure the short term efficacy of the nevirapine treatment following efavirenz withdrawal. -To compare the safety of the initial full dose nevirapine treatment with the dose escalation nevirapine treatment.
 -To determine efavirenz plasma levels prior to its withdrawal and on days 3, 7 and 14 after it.
 -To know treatment compliance after switching from efavirenz to nevirapine.
 -To know the evolution of the neuropsychiatric adverse reactions to efavirenz that caused its withdrawal.
 
 |  | 
| E.2.3 | Trial contains a sub-study | Information not present in EudraCT | 
| E.3 | Principal inclusion criteria | 
| 1. Age >18 years old 2. Chronic HIV-1 infection confirmed with Western Blot.
 3. Patients treated with an efavirenz containing HAART regimen for a minimum of 15 days prior to visit-1.
 4. Patients presenting any neuropsychiatric adverse reactions to efavirenz (check Annex D list) and requiring its withdrawal.
 5. Ability of the patient to follow the treatment during the planned period.
 6. Acceptance and signing of the informed consent.
 
 |  | 
| E.4 | Principal exclusion criteria | 
| 1. Hepatic function laboratory values (AST, ALT, GGT) > 3 times the upper normal limit. 2. Serum creatinine >1.5 mg/dl.
 3. CD4+ T-lymphocyte values > 400 cells/ml for males or >250 cells/ml for females unless the benefits overcome the risks (technical data file warning) and always under the investigator´s judgement.
 4. HIV plasma viral load > 50 copies/ml, in those patients with more than 3 months of treatment with efavirenz.
 5. Suspected or confirmed efavirenz and/or nevirapine resistance (e.g. previous virologic failure in a treatment regimen containing one NN-RTI) .
 6. Patients currently taking any medicines that could interfere with the absorption, distribution or metabolism of nevirapine (check Annex E).
 7. Presence of infections and/or opportunistic neoplasias during the 3 months prior to the entry in the clinical trial.
 8. Any condition or medical conditions that in the investigator´s opinion, could interfere with the ability of the subject to take part or comply with the requirements of this protocol.
 9. Pregnancy.
 10. Suspected primary infection less than 6 months long.
 |  | 
| E.5 End points | 
| E.5.1 | Primary end point(s) | 
| The proportion of patients with nevirapine trough plasma concentration within therapeutic levels after 7 days of treatment. |  | 
| E.6 and E.7 Scope of the trial | 
| E.6 | Scope of the trial | 
| E.6.1 | Diagnosis | No | 
| E.6.2 | Prophylaxis | No | 
| E.6.3 | Therapy | Yes | 
| E.6.4 | Safety | Yes | 
| E.6.5 | Efficacy | Yes | 
| E.6.6 | Pharmacokinetic | Yes | 
| E.6.7 | Pharmacodynamic | No | 
| E.6.8 | Bioequivalence | No | 
| E.6.9 | Dose response | No | 
| E.6.10 | Pharmacogenetic | Information not present in EudraCT | 
| E.6.11 | Pharmacogenomic | No | 
| E.6.12 | Pharmacoeconomic | No | 
| E.6.13 | Others | No | 
| E.7 | Trial type and phase | 
| E.7.1 | Human pharmacology (Phase I) | No | 
| E.7.1.1 | First administration to humans | Information not present in EudraCT | 
| E.7.1.2 | Bioequivalence study | Information not present in EudraCT | 
| E.7.1.3 | Other | Information not present in EudraCT | 
| E.7.1.3.1 | Other trial type description |  | 
| E.7.2 | Therapeutic exploratory (Phase II) | No | 
| E.7.3 | Therapeutic confirmatory (Phase III) | Yes | 
| E.7.4 | Therapeutic use (Phase IV) | Yes | 
| E.8 Design of the trial | 
| E.8.1 | Controlled | Yes | 
| E.8.1.1 | Randomised | Yes | 
| E.8.1.2 | Open | Yes | 
| E.8.1.3 | Single blind | No | 
| E.8.1.4 | Double blind | No | 
| E.8.1.5 | Parallel group | No | 
| E.8.1.6 | Cross over | No | 
| E.8.1.7 | Other | No | 
| E.8.2 | Comparator of controlled trial | 
| E.8.2.1 | Other medicinal product(s) | Yes | 
| E.8.2.2 | Placebo | No | 
| E.8.2.3 | Other | No | 
| E.8.3 | The trial involves single site in the Member State concerned | No | 
| E.8.4 | The trial involves multiple sites in the Member State concerned | Yes | 
| E.8.5 | The trial involves multiple Member States | No | 
| E.8.6 Trial involving sites outside the EEA | 
| E.8.6.1 | Trial being conducted both within and outside the EEA | No | 
| E.8.6.2 | Trial being conducted completely outside of the EEA | Information not present in EudraCT | 
| E.8.7 | Trial has a data monitoring committee | Information not present in EudraCT | 
| E.8.8 | Definition of the end of the trial and justification where it is not the last
                        visit of the last subject undergoing the trial |  | 
| E.8.9 Initial estimate of the duration of the trial | 
| E.8.9.1 | In the Member State concerned years | 1 | 
| E.8.9.1 | In the Member State concerned months | 3 | 
| E.8.9.1 | In the Member State concerned days |  |