Criteria for vital signs abnormalities of potential concern included: supine/standing systolic blood pressure (BP) (less than [<] 90 millimeter of mercury [mmHg], maximum [max] decrease and increase of greater than or equal to [>=] 30 mmHg from baseline); diastolic BP (<50 mmHg, maximum decrease and increase of >=20 mmHg from baseline); supine pulse rate <40 beats per minute [bpm] or greater than [>]120 bpm); standing pulse rate <40 bpm or >140 bpm. Baseline is defined as the last pre-dose (PF-04447943) recording at Day 0.

Safety analysis set included all participants who had received at least 1 dose of study medication.

Criteria for ECG abnormalities of potential clinical concern included: PR interval (>=300 milliseconds [msec], >= 25 percent [%] increase when baseline >200 msec or increase >=50% when baseline less than or equal to [<=] 200 msec); QRS interval (>=200 msec, >= 25% increase when baseline >100 msec or increase >=50% when baseline <=100 msec); QT corrected using Fridericia's formula (QTcF) (>=500 msec, maximum increase between >=30 to <60 msec and >=60 msec). Baseline is defined as the last pre-dose (PF-04447943) recording at Day 0.

Safety analysis set included all participants who had received at least 1 dose of study medication.

Criteria for laboratory tests abnormalities included: hemoglobin, hematocrit (<0.8*lower limit of normal [LLN]); red blood cell count (<0.8*LLN); platelets (<0.5*LLN or >1.75* upper limit of normal [ULN]); leucocytes (<0.6*LLN or >1.5*ULN); lymphocytes, total neutrophils (<0.8*LLN or >1.2*ULN); basophils, eosinophils, monocytes (>1.2*ULN); total bilirubin (>1.5* ULN); aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase (>3*ULN); creatinine, blood urea nitrogen (>1.3*ULN); glucose (<0.6*LLN or >1.5*ULN); uric acid (>1.2*ULN); sodium (<0.95*LLN or 1.05*ULN); potassium, calcium, chloride, bicarbonate (<0.9*LLN or 1.1*ULN); albumin, total protein (<0.8*LLN or 1.2*ULN); urine analysis. Total number of participants with any laboratory abnormalities was reported.

Safety analysis set included all participants who had received at least 1 dose of study medication.

An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent are events between first dose of study drug and up to Day 10 after last dose that were absent before treatment or that worsened relative to pretreatment state. Any abnormalities related to physical and neurological findings, laboratory tests, vital signs and ECG were reported as adverse events. AEs included SAEs as well as non-serious AEs which occurred during the trial.

Safety analysis set included all participants who had received at least 1 dose of study medication.

Pharmacokinetic (PK) concentration analysis set included all randomized participants who had received at least one dose of PF-04447943 and had at least 1 evaluable PF-04447943 concentration. Here, 'number analyzed, n' signifies those participants who were evaluable at specified time point.

Area under the plasma concentration time-curve from time zero to end of dosing interval (tau), where dosing interval is 12 hours.

PK analysis set included all randomized participants who had received at least one dose of PF-04447943 and had at least 1 of the PK parameters of interest for PF-04447943. Here, 'n' signifies those participants who were evaluable at specified time point.

PK analysis set included all randomized participants who had received at least one dose of PF-04447943 and had at least 1 of the PK parameters of interest for PF-04447943. Here, 'n' signifies those participants who were evaluable at specified time point.

PK analysis set included all randomized participants who had received at least one dose of PF-04447943 and had at least 1 of the PK parameters of interest for PF-04447943. Here, 'n' signifies those participants who were evaluable at specified time point.

PK concentration analysis set included all randomized participants who had received donepezil and had at least 1 evaluable donepezil concentration. Here, 'n' signifies those participants who were evaluable at specified time point.

Area under the plasma concentration time-curve from time zero to end of dosing interval (tau), where dosing interval is 24 hours.

PK analysis set included all randomized participants who had received donepezil and had at least 1 of the PK parameters of interest of donepezil. Here, 'n' signifies those participants who were evaluable at specified time point.

PK analysis set included all randomized participants who had received donepezil and had at least 1 of the PK parameters of interest of donepezil. Here, 'n' signifies those participants who were evaluable at specified time point.

PK analysis set included all randomized participants who had received donepezil and had at least 1 of the PK parameters of interest of donepezil. Here, 'n' signifies those participants who were evaluable at specified time point.