J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website https://jocmr.elmerjournals.com

Original Article

Volume 17, Number 9, October 2025, pages 499-506

Effectiveness of Antibiotic Regimens in Reducing White Blood Cell Count Within Three to Five Days in Febrile Leukocytosis Treated With Ambulatory Therapy

↓ Figure 2. Unadjusted and adjusted white blood cell counts over time by treatment regimen (adjusted for age, pre-treatment white blood cell count, and pre-treatment percentage of polymorphonuclear neutrophils).

↓ **Table 1.** Baseline Characteristics
Baseline characteristics	Missing	Regimen A (n = 64), n (%)	Regimen B (n = 128), n (%)	Regimen C (n = 58), n (%)	P value
Regimen A: IV ceftriaxone for 1 day, then oral cefixime; Regimen B: IV ceftriaxone for 3 days, then oral cefixime; Regimen C: IV ceftriaxone plus oral doxycycline concurrently for 3 days, then continue oral doxycycline. IQR: interquartile range; PMN: polymorphonuclear neutrophils; SD: standard deviation; Tx: treatment; WBC: white blood cell.
Female	0	47 (73.4)	80 (62.5)	31 (53.4)	0.075
Age (years), mean ± SD	0	44.5 ± 21.4	52.3 ± 21.4	48.8 ± 21.1	0.057
Body mass index (kg/m²), mean ± SD	0	23.1 ± 4.5	23.2 ± 5.1	23.5 ± 6.0	0.909
Temperature (°C), mean ± SD	0	38.5 ± 0.6	38.5 ± 0.5	38.6 ± 0.6	0.793
Symptoms
Respiratory	0	6 (9.4)	10 (7.8)	2 (3.5)	0.692
Gastrointestinal	0	8 (12.5)	13 (10.2)	10 (17.2)
Genitourinary	0	6 (9.4)	14 (10.9)	4 (6.9)
Non-specific	0	44 (68.7)	91 (71.1)	42 (72.4)
Comorbidity
Diabetes Mellitus	0	15 (23.4)	30 (23.4)	19 (32.8)	0.379
Hypertension	0	16 (25.0)	43 (33.6)	15 (25.9)	0.378
Dyslipidemia	0	10 (15.6)	21 (16.4)	13 (22.4)	0.564
Chronic kidney disease	0	3 (4.7)	12 (9.4)	9 (15.5)	0.126
Pre-Tx WBC (× 10³/µL), median (IQR)	0	15.4 (13.5 - 17.5)	15.8 (13.6 - 18.1)	15.4 (13.7 - 18.1)	0.664
Pre-Tx PMN (%), mean ± SD	0	82.0 ± 10.1	82.7 ± 9.5	80.9 ± 9.6	0.361
Time to follow-up (h), mean ± SD	0	73.0 ± 12.2	71.9 ± 11.4	70.6 ± 10.6	0.562

↓ Table 1. Baseline Characteristics

Baseline characteristics

Missing

Regimen A (n = 64), n (%)

Regimen B (n = 128), n (%)

Regimen C (n = 58), n (%)

P value

Regimen A: IV ceftriaxone for 1 day, then oral cefixime; Regimen B: IV ceftriaxone for 3 days, then oral cefixime; Regimen C: IV ceftriaxone plus oral doxycycline concurrently for 3 days, then continue oral doxycycline. IQR: interquartile range; PMN: polymorphonuclear neutrophils; SD: standard deviation; Tx: treatment; WBC: white blood cell.

Female

47 (73.4)

80 (62.5)

31 (53.4)

0.075

Age (years), mean ± SD

44.5 ± 21.4

52.3 ± 21.4

48.8 ± 21.1

0.057

Body mass index (kg/m²), mean ± SD

23.1 ± 4.5

23.2 ± 5.1

23.5 ± 6.0

0.909

Temperature (°C), mean ± SD

38.5 ± 0.6

38.5 ± 0.5

38.6 ± 0.6

0.793

Symptoms

Respiratory

6 (9.4)

10 (7.8)

2 (3.5)

0.692

Gastrointestinal

8 (12.5)

13 (10.2)

10 (17.2)

Genitourinary

6 (9.4)

14 (10.9)

4 (6.9)

Non-specific

44 (68.7)

91 (71.1)

42 (72.4)

Comorbidity

Diabetes Mellitus

15 (23.4)

30 (23.4)

19 (32.8)

0.379

Hypertension

16 (25.0)

43 (33.6)

15 (25.9)

0.378

Dyslipidemia

10 (15.6)

21 (16.4)

13 (22.4)

0.564

Chronic kidney disease

3 (4.7)

12 (9.4)

9 (15.5)

0.126

Pre-Tx WBC (× 10³/µL), median (IQR)

15.4 (13.5 - 17.5)

15.8 (13.6 - 18.1)

15.4 (13.7 - 18.1)

0.664

Pre-Tx PMN (%), mean ± SD

82.0 ± 10.1

82.7 ± 9.5

80.9 ± 9.6

0.361

Time to follow-up (h), mean ± SD

73.0 ± 12.2

71.9 ± 11.4

70.6 ± 10.6

0.562

↓ **Table 2.** Crude Pre- and Post-Treatment White Blood Cell Counts Across Three Antibiotic Regimens
Regimens	Pre-treatment WBC (× 10³ cells/mm³), median (p25, p75)	P value	Post-treatment WBC (× 10³ cells/mm³), median (p25, p75)	P value
Values are presented as median (25th percentile, 75th percentile). WBC: white blood cell count; Regimen A: IV ceftriaxone for 1 day, then oral cefixime; Regimen B: IV ceftriaxone for 3 days, then oral cefixime; Regimen C: IV ceftriaxone plus oral doxycycline concurrently for 3 days, then continue oral doxycycline; IV: intravenous.
Regimen A	15.4 (13.5, 17.5)	0.664	8.7 (7.2, 9.6)	0.612
Regimen B	15.8 (13.6, 18.1)		8.9 (7.9, 9.6)
Regimen C	15.4 (13.7, 18.1)		8.9 (6.9, 9.4)

↓ Table 2. Crude Pre- and Post-Treatment White Blood Cell Counts Across Three Antibiotic Regimens

Regimens

Pre-treatment WBC (× 10³ cells/mm³), median (p25, p75)

P value

Post-treatment WBC (× 10³ cells/mm³), median (p25, p75)

P value

Values are presented as median (25th percentile, 75th percentile). WBC: white blood cell count; Regimen A: IV ceftriaxone for 1 day, then oral cefixime; Regimen B: IV ceftriaxone for 3 days, then oral cefixime; Regimen C: IV ceftriaxone plus oral doxycycline concurrently for 3 days, then continue oral doxycycline; IV: intravenous.

Regimen A

15.4 (13.5, 17.5)

0.664

8.7 (7.2, 9.6)

0.612

Regimen B

15.8 (13.6, 18.1)

8.9 (7.9, 9.6)

Regimen C

15.4 (13.7, 18.1)

8.9 (6.9, 9.4)

↓ **Table 3.** White Blood Cell Reduction at 3-Day Follow-Up After Quantile Regression Analysis With Inverse Probability of Treatment Weighting
Regimens	WBC reduction (× 10³ cells/mm³)	95% confidence interval	P value^a
^aOverall P value derived from a Wald test. WBC: white blood cell count; Regimen A: IV ceftriaxone for 1 day, then oral cefixime; Regimen B: IV ceftriaxone for 3 days, then oral cefixime; Regimen C: IV ceftriaxone plus oral doxycycline concurrently for 3 days, then continue oral doxycycline; IV: intravenous.
Regimen A	-6.6	-7.0 to -6.2	0.484
Regimen B	-6.8	-7.2 to -6.5
Regimen C	-6.9	-7.5 to -6.3

↓ Table 3. White Blood Cell Reduction at 3-Day Follow-Up After Quantile Regression Analysis With Inverse Probability of Treatment Weighting

Regimens

WBC reduction (× 10³ cells/mm³)

95% confidence interval

P value^a

^aOverall P value derived from a Wald test. WBC: white blood cell count; Regimen A: IV ceftriaxone for 1 day, then oral cefixime; Regimen B: IV ceftriaxone for 3 days, then oral cefixime; Regimen C: IV ceftriaxone plus oral doxycycline concurrently for 3 days, then continue oral doxycycline; IV: intravenous.

Regimen A

-6.6

-7.0 to -6.2

0.484

Regimen B

-6.8

-7.2 to -6.5

Regimen C

-6.9

-7.5 to -6.3

↓ **Table 4.** Pairwise Comparisons of WBC Reduction Between Antibiotic Regimens Using Wald’s Test With Bonferroni-Adjusted P Values
Regimens	A	B	C
Regimen A: IV ceftriaxone for 1 day, then oral cefixime; Regimen B: IV ceftriaxone for 3 days, then oral cefixime; Regimen C: IV ceftriaxone plus oral doxycycline concurrently for 3 days, then continue oral doxycycline; IV: intravenous.
A	-	-	-
B	0.727		-
C	0.337	0.233	-

↓ Table 4. Pairwise Comparisons of WBC Reduction Between Antibiotic Regimens Using Wald’s Test With Bonferroni-Adjusted P Values

Regimens

0.727

0.337

0.233

↓ **Table 5.** Secondary Clinical Outcomes Across the Three Antibiotic Regimens
Regimens	A (n = 64), n (%)	B (n = 128), n (%)	C (n = 58), n (%)	P value
Regimen A: IV ceftriaxone for 1 day, then oral cefixime; Regimen B: IV ceftriaxone for 3 days, then oral cefixime; Regimen C: IV ceftriaxone plus oral doxycycline concurrently for 3 days, then continue oral doxycycline; IV: intravenous.
Improved	51 (79.7)	110 (85.9)	52 (89.7)	0.283
Continued or switched IV antibiotics	13 (20.3)	18 (14.1)	6 (10.3)
Admitted	0 (0)	0 (0)	0 (0)

↓ Table 5. Secondary Clinical Outcomes Across the Three Antibiotic Regimens

Regimens

A (n = 64), n (%)

B (n = 128), n (%)

C (n = 58), n (%)

P value

Improved

51 (79.7)

110 (85.9)

52 (89.7)

0.283

Continued or switched IV antibiotics

13 (20.3)

18 (14.1)

6 (10.3)

Admitted

0 (0)