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A controlled trial of tacrine in Alzheimer's disease. The Tacrine Study Group
Farlow M, Gracon SI, Hershey LA, Lewis KW, Sadowsky CH, Dolan-Ureno J.. JAMA, 1992-11-01
Topic: Drug trials: efficacy and safety
Objective To compare efficacy and safety of tacrine hydrochloride with placebo in patients with probable Alzheimer's disease. Design A 12-week, double-blind, placebo-controlled, parallel-group study. Setting Outpatients at 23 centers. Patients Men and women with probable Alzheimer's disease, at least 50 years old, mildly to moderately impaired, without other significant medical conditions. Interventions In the initial 6 weeks, patients received placebo, 20 mg/d of tacrine, or 40 mg/d of tacrine. In the second 6 weeks, half received the same treatment and half increased tacrine dose: those receiving placebo increased to 20 mg/d, those receiving 20 mg/d increased to 40 mg/d, and those receiving 40 mg/d increased to 80 mg/d. Primary outcome measures Alzheimer's Disease Assessment Scale (ADAS) cognitive component and clinician-rated Clinical Global Impression of Change (CGIC). Results Four hundred sixty-eight patients entered. After 12 weeks, dose-related improvement was significant on the ADAS cognitive (P = .014), clinician-rated CGIC (P = .014), and caregiver-rated CGIC (P = .006). Comparison of 80 mg/d with placebo showed significant improvement on the ADAS cognitive (P = .015), clinician-rated CGIC (P = .016), and caregiver-rated CGIC (P = .028). Significant effects appeared as early as 6 weeks on the ADAS cognitive and caregiver-rated CGIC. Among patients receiving 80 mg/d of tacrine, 51% achieved a four-point or greater improvement of the ADAS cognitive component after 12 weeks of treatment. Reversible asymptomatic transaminase elevations greater than three times normal occurred in 25% of patients. Other treatment-related events included nausea and/or vomiting (8%), diarrhea (5%), abdominal pain (4%), dyspepsia (3%), and rash (3%). Conclusions These results confirm the efficacy and safety of tacrine in some patients with Alzheimer's disease. After 12 weeks, the magnitude of the treatment effect is clinically important and recognized by the physician and caregiver. Liver toxicity is reversible and easily detected by weekly alanine aminotransferase determinations.
Key findings
- Patients Men and women with probable Alzheimer's disease, at least 50 years old, mildly to moderately impaired, without other significant medical conditions.
- Results Four hundred sixty-eight patients entered.
- After 12 weeks, dose-related improvement was significant on the ADAS cognitive (P = .014), clinician-rated CGIC (P = .014), and caregiver-rated CGIC (P = .006).
- Comparison of 80 mg/d with placebo showed significant improvement on the ADAS cognitive (P = .015), clinician-rated CGIC (P = .016), and caregiver-rated CGIC (P = .028).
- Significant effects appeared as early as 6 weeks on the ADAS cognitive and caregiver-rated CGIC.
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Study details
- Evidence strengthLow
How this study scored 69/100
Published in a top-tier journal, and it is a randomised controlled trial. Scored zero for sample size and effect reported because the record does not state it. We have no data on journal's citation record, times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record and institution's track record, so those were left out: it earned 42 of the 61 points we could judge it on, which is 69 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 10 / 10 | Tier 1 — top-tier general journal (JAMA) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 11 / 12 | A randomised controlled trial (from PubMed type “Randomized Controlled Trial”) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 1992 — older than 20 years, still counted |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (pubmed indexes it as a clinical or observational study) |
| Randomised / blinded | 2 / 2 | Randomised and blinded or placebo-controlled (as stated in the record) |
| Times cited | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | 2 / 3 | PubMed indexes it as a multicentre study |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 1404819) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 42 / 61 | Scored on 12 of 20 parts. We have no data for the rest, so they are left out: 42 of the 61 points we could judge it on is 69 out of 100. |
| Total | 69 / 100 | — |
What each of these 20 components measures, and what this score is not →
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
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APA 7th
Farlow, M., Gracon, S. I., Hershey, L. A., Lewis, K. W., Sadowsky, C. H., & Dolan-Ureno, J. (1992). A controlled trial of tacrine in Alzheimer's disease. The Tacrine Study Group. JAMA. https://doi.org/10.1001/jama.1992.03490180055026
Vancouver
Farlow M, Gracon SI, Hershey LA, Lewis KW, Sadowsky CH, Dolan-Ureno J. A controlled trial of tacrine in Alzheimer's disease. The Tacrine Study Group. JAMA. 1992. doi:10.1001/jama.1992.03490180055026. PMID: 1404819.
BibTeX
@article{farlow1992-1404819,
author = {Farlow, M. and Gracon, S. I. and Hershey, L. A. and Lewis, K. W. and Sadowsky, C. H. and Dolan-Ureno, J.},
title = {{A controlled trial of tacrine in Alzheimer's disease. The Tacrine Study Group}},
journal = {JAMA},
year = {1992},
doi = {10.1001/jama.1992.03490180055026},
pmid = {1404819},
url = {https://doi.org/10.1001/jama.1992.03490180055026}
}