Here is the design of a clinical trial:

Official Title: The Reduction Effect of Oral Pravastatin on Acute Phase Response of Intravenous Zoledronic Acid: a Real-world Study

Included conditions:
- Postmenopausal Osteoporosis

Study Armgroups:
- {'label': 'pravastatin 80mg/d', 'type': 'EXPERIMENTAL', 'description': 'Oral administration of pravastatin at 1 h before zoledronic acid infusion, 24 h and 48 h after zoledronic acid infusion', 'interventionNames': ['Drug: Pravastatin Sodium 80 MG']}
- {'label': 'placebo', 'type': 'PLACEBO_COMPARATOR', 'description': 'Oral administration of placebo at 1 h before zoledronic acid infusion, 24 h and 48 h after zoledronic acid infusion', 'interventionNames': ['Drug: Placebo']}

Interventions:
- {'type': 'DRUG', 'name': 'Pravastatin Sodium 80 MG', 'description': 'daily oral administration of 80mg', 'armGroupLabels': ['pravastatin 80mg/d'], 'otherNames': ['Meibailezhen']}
- {'type': 'DRUG', 'name': 'Placebo', 'description': 'daily oral administration', 'armGroupLabels': ['placebo'], 'otherNames': ['Meibailezhen placebo']}

Primary Outcomes:
- {'measure': 'Incidence of acute phase response', 'description': 'Effect of oral pravastatin on the incidence of acute phase response within 72 hours after zoledronic acid infusion', 'timeFrame': '0-72 hours'}

Please estimate the sample size based on the assumption: 
The number of events per variable is selected to be 10. A 10% loss to follow-up is considered.
Sample size
        This study adopts a real-world prospective non-randomised controlled clinical trial design method. Considering that there may be 4â6 factors associated with baseline variables (including intervention), the number of events per variable was selected to be 10.16â18 After the adjustment of five factors, such as age, body weight, height, BMD and intervention, approximately (10Ã5=) 50 participants in each arm were deemed necessary. In addition, considering a 10% loss to follow-up, 55 participants will be needed for each arm for a total of 110 participants.