01 Ask for clearance, not a creatinine selfie
Creatinine 2.1 means little without age, weight, and sex. The insert names Cockcroft-Gault for outpatients. A phone eGFR from 2021 is not that number. Elderly people sit in middle rows without anyone saying "renal."
The leaf reprints the table. This ink is the 400 mg-shaped reading of it. The titration margin is the sedation ramp when kidneys still work.
Hemodialysis removes gabapentin. A post-dialysis supplement is on the table (125-350 mg in the listed steps). This margin will not pick yours.
02 How to ask for a clearance instead of a creatinine selfie
Age, weight, sex, and a current creatinine go into Cockcroft-Gault, the estimate the insert names. A phone eGFR from 2021 is not that number. A creatinine of 2.1 is not a row.
Elderly people sit in middle rows without anyone saying renal. Ask before a 90-count refill of 400 mg if weight dropped or an ACE inhibitor started.
The ≥60 row is where 400 mg TID lives. 30-59 can list 400 mg BID. 15-29 can list 400 mg QD. At 15 mL/min the daily range is 100-300 mg. One 400 mg capsule overshoots that day.
Hemodialysis: maintenance by residual clearance plus a listed post-HD supplement. Do not invent the supplement as an extra 400 mg because "dialysis washed it out."
The leaf reprints the table. This ink is the 400 mg reading.
03 Why sleepiness showed up on a dose that used to be fine
A single 400 mg study dose lasted about 6.5 hours when CrCl was over 60 and about 52 hours when CrCl was under 30. Plasma clearance fell from about 190 mL/min to 20. "I got sensitive" is often clearance.
Adding an opioid on top of a now-daily 400 mg that should have been 200 mg is how chairs become dangerous.
Do not switch to every-other-day from a 400 mg bottle. QOD is not a printed row. Ask for a strength that matches.
Do not nibble capsules to fake 200 mg unless a pharmacist prepared that split.
Get a new number. Then rewrite the calendar. Then climb again only if they say so. See the titration margin.
04 Tuesday dialysis is not a folk extra-400 day
Bring the 400 mg bottle, the written daily pattern, and the post-HD piece if they wrote one. Tuesday/Thursday/Saturday is not a reason to invent an extra capsule.
If residual function changed, the maintenance row changed. Say the last weight.
Antacids on dialysis days still need the two-hour space.
Elise read the 52-hour half-life against the 400 mg renal-impairment paragraph. Mail us if we left 400 mg TID on a CrCl-20 row without a warning.
Hepatic shrugs do not clear a high creatinine. Gabapentin is not metabolized there.
05 Why a dose that used to be fine now lasts all day
A single 400 mg study dose lasted about 6.5 hours when CrCl was over 60 and about 52 hours when CrCl was under 30. Plasma clearance fell from about 190 mL/min to 20. "I got sensitive" is often clearance.
Adding an opioid on top of a now-daily 400 mg that should have been 200 mg is how chairs become dangerous.
Do not switch to every-other-day from a 400 mg bottle. QOD is not a printed row. Ask for a strength that matches.
Do not nibble capsules to fake 200 mg unless a pharmacist prepared that split.
Get a new number. Then rewrite the calendar. Then climb again only if they say so. See the titration margin.
06 Read the 400 mg capsule against each row
≥60 mL/min: 900-3600 mg/day. 400 mg three times daily (1200 mg) lives here. 30-59: 400-1400 mg/day; 400 mg twice daily is a listed option. 15-29: 200-700 mg/day; 400 mg once daily is a listed option. 15 mL/min: 100-300 mg/day. A 400 mg capsule overshoots that entire day.
Below 15, the insert says reduce in proportion (example: 7.5 mL/min gets half the 15 mL/min daily dose). You will not do that arithmetic from a 400 mg bottle at home.
If the bottle is only 400 mg and the row wants 300 mg, ask for another strength. Do not nibble capsules.
| CrCl (mL/min) | 400 mg-shaped pattern (label options) |
|---|---|
| >= 60 | 400 mg TID is on the table (inside 900-3600) |
| 30-59 | 400 mg BID is on the table (inside 400-1400) |
| 15-29 | 400 mg QD is on the table (inside 200-700) |
| 15 | 400 mg is above the 100-300 daily range |
| HD | Maintenance by clearance plus a listed post-HD supplement |
07 What to bring to dialysis Tuesday
The 400 mg bottle, the written daily pattern, and the post-HD piece if they wrote one. Tuesday/Thursday/Saturday is not a folk extra-400 day.
If residual function changed, the maintenance row changed. Say the last weight.
Antacids on dialysis days still need the two-hour space.
Elise read the 52-hour half-life against the 400 mg renal-impairment paragraph. Mail us if we left 400 mg TID on a CrCl-20 row without a warning.
Hepatic shrugs do not clear a high creatinine. Gabapentin is not metabolized there.
08 The "I got sensitive" story is often clearance
Plasma clearance in that 400 mg study fell from about 190 mL/min to 20 as kidneys failed. People call it age or "the drug changed." The interval needed to change. Adding an opioid on top of a now-daily 400 mg that should have been 200 mg is how chairs become dangerous.
Get a new clearance before a 90-count refill if weight dropped, if ACE inhibitors started, or if the person is simply a year older.
09 How to turn a creatinine into a row instead of a feeling
Age, weight, sex, and a current creatinine go into Cockcroft-Gault, the estimate the insert names. A phone eGFR from 2021 is not that number. A creatinine of 2.1 is not a row.
Elderly people sit in middle rows without anyone saying renal. Ask before a 90-count refill of 400 mg if weight dropped or an ACE inhibitor started.
The ≥60 row is where 400 mg TID lives. 30-59 can list 400 mg BID. 15-29 can list 400 mg QD. At 15 mL/min the daily range is 100-300 mg. One 400 mg capsule overshoots that day.
Hemodialysis: maintenance by residual clearance plus a listed post-HD supplement. Do not invent the supplement as an extra 400 mg because "dialysis washed it out."
The leaf reprints the table. This ink is the 400 mg reading.
10 Fewer swallows, same 400 mg print, different day
Reviewed 21 August 2026, Elise Moreau.
Ask for Cockcroft-Gault, not a selfie creatinine and not a 2021 eGFR. The ≥60 row is where 400 mg three times a day lives. At 15 mL/min the daily range is 100-300 mg. One 400 mg capsule already overshoots that day. Hemodialysis uses a listed post-HD piece, not a folk extra capsule.
A 400 mg study dose lasted about 6.5 hours when clearance was high and about 52 hours when it was low. Sleepiness on a previously tolerated TID is often that math. Get a new number. Then rewrite the calendar.
The leaf reprints the table. The titration margin is the climb. Mail [email protected] if we left 400 mg TID on a CrCl-20 row.
An 8 kg weight loss can move Cockcroft-Gault. Ask before the next 90-count. An eGFR of 48 is not a row by itself. Bring age, weight, sex, and the current creatinine. Close enough on 400 mg BID is their sentence after they compute the estimate, not a Bordeaux yes from a phone number.
If they wrote 200 mg daily and the pharmacy only has 400 mg, do not invent alternate days. QOD is not a printed row. Ask them to fix the fill. Do not silently take 400 mg TID because that is how you used to take it when kidneys were better. Antacids on dialysis days still need the two-hour space.
Tuesday dialysis is not a folk extra-400 day. Bring the bottle, the written daily pattern, and the post-HD piece if they wrote one. If residual function changed, the maintenance row changed. Say the last weight. Hepatic shrugs do not clear a high creatinine. Gabapentin is not metabolized there.
A creatinine of 2.1 is not a row. A phone eGFR from 2021 is not Cockcroft-Gault. Elderly people sit in middle rows without anyone saying renal. Ask before a 90-count refill of 400 mg if an ACE inhibitor started. Sleepiness on a previously tolerated TID is often clearance.
Do not nibble capsules to fake 200 mg unless a pharmacist prepared that split.