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Antiemetics
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What they do: |
- Move SN to intestines quickly
- Reduce vomiting
It's not just to 'reducing nausea' – prevent serious vomiting (complex stomach-brain interactions) and open GI valves (sphincters). |
Do I need it? | No, though recommended.
- Many used SN fatally without AE
- Many vomited even with AE
Success / vomiting varies, so there is no definitive answer.
May be quicker and peaceful , but as Stan noted AEs are not required (may skip if trouble getting). |
Are they available? | Depends on country .
- Usually prescription only
- OTC – UK, Brazil, Spain
- Otherwise many acquired AE with little trouble:
- Easy to ask a physician – example (original post)
- Search Internet , many online pharmacies
- Consult existing threads (others looking for it)
Importing prescription-only meds without prescription is illegal.
Antiemetics are very common , not "restricted substance" , investigation unlikely.
Forging prescription is a crime (don't). |
Warnings: | CAUTION
- Read medication side effects and warnings
- Meto & Prochlorperazine may cause problems.
- Others also have side-effects, for heart conditions etc.
- Check contraindication to existing meds – drug interaction calculator
- Test small dosage before ctb date
- Mild effects – try small dose 8h later (tolerance = less side effects)
- Severe effects – avoid.
- Do not combine AEs from the 19 mentioned – use just one type
- If Olanzapine taken – don't add Meto ; Quetiapine taken – don't add Meto
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Types |
- 6 AEs – antiemetics – 3 of which are very common
- 13 APs – antipsychotics
All 19 medications are potent .
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Antiemetics (6) | |
most common | .
1. Dromperidone
2. Metoclopramide
3. Prochlorperazine |
| 4. Olanzapine
5. Alizapride
6. Chlorpromazine .
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Will any antiemetic work? | NO.
Guide provides 6 AEs – only use those.
- Must target dopamine (Domperidone, Prochlorperazine)
- Preferably serotonin in addition (Metoclopramide)
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"Alternatives to Meto" | Yes . Plenty .
- Domperidone (with or without Ondansetron) , or Buccastem.
- There's a list – use it...
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Will X work as AE? | If not in guide and you've searched threads, then NO. |
AEs in detail | |
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Substance | Brand name | Indication | Availability | EPS Risk | D2 | 5HT3A | 1. Domperidone | Motilium | AE | Banned in US
OTC in Asia | None | 7.5 | - | 2. Metoclopramide | Reglan, Primperan
brands | AE | Rx
OTC in Spain, Brasil, Asia | Low- 0.2% | 7.5 | 6.2 | 3. Prochlorperazine | Buccastem
brands | Antipsychotic
AE | OTC in UK | HIGH- 5% | 8.4 | - | | | | | | | | 4. Olanzapine | Zyprexa
brands | Antipsychotic
CINV | Rx | Medium- 2% | 8.7 | - | 5. Alizapride | | AE | Rx | | | | 6. Chlorpromazine | Thorazine, Largactil | Antipsychotic
AE | Rx | HIGH- 5% | 7.5 | - |
Domperidone efficient as Metoclopramide (research).
Stan used Buccastem.
Olanzapine very effective [1][2] |
sources & notes |
- "No EPS": scarce cases
- Receptor Affinity: higher is "stronger" ; 1 pKi (100mM) – 9 pKi (10 nM)
- Effectiveness: mg ~ nM ~ effetive . Though not definitive (simple maths) .
- Therapeutic dose of a drug (mg) correlates to affinity for D2 receptor (low nM)
- Average clinical potency (effective) correlates to affinity for dopamine receptors
- Any drug with Ki < 50 nM would be remarkably helpful
- Drugs above 4 pKi are considered to be binding [1]
Sources:
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Other AEs? | DO NOT use –
- Ondansetron/Zofran
- Diphenhydramine/Benadryl
- Dimenhydrinate/Dramamine
Serotonin or Histamine only are not as effective.
Read guide ; List of AE by type – dopamine antagonists (Wikipedia) |
Why not Dramamine? | Histmine is responsible for body movements (Vestibular nucleus) , treats motion sickness
- Little to do with poisons, stomach, or CTZ .
- Lack prokinetic activity
- See here
Dramamine is not a good solution , though won't harm (unkown why PPH push these) |
Why not Ondansetron? |
"Metoclopramide is used by Dignitas and i think it's the recommened antiemetic in OD, the second one being domperidone, both dopamine antagonists. Ondansetron (Zofran) is a serotonin receptor antagonist and it's used for cancer patients undergoing chemotherapy because the irritation of the GI mucosa by the medication used in chemotherapy (which is cytotoxic and increase the levels of serotonin in the blood) are transmitted through the vagal nerve to the chemoreceptor trigger zone via activating serotonin receptors (5-HT3). It has no effect on dopamine receptors. "
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In simple words? | Need broad systematic AE targeting both CTZ (brain) and stomach plus prokinetic. |
How vomiting works | Complex interactions:
- Chemoreceptor Trigger Zone
- Vomiting Centre
- Nucleus Tractus Solitarius
- GI tract chemoreceptors
See graphic schema .
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Antipsychotics | (13) |
What are they? | If you do not take these regularly – DO NOT USE – this section is not for you.
They affect over weeks – so only if it is your regular medication.
- Droperidol, Benperidol, Trifuperidol, Spiperone, Haloperidol, Bromperidol, Lurasidone, Sestindole, Paliperidone, Risperidone, Olanzapine, Clozapine, Quetiapine
- Stan listed with nM (receptor affinity); lower numbers may indicate stronger effects.
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Warnings: | CAUTION
- Abrupt dosage change – harmful
- Tampering is done over weeks
- EPS effects
- Harsh withdrawal (psychosis)
Therefore
- Don't take a single dose
- Don't double dose
- Don't change prescribed dosage
- Don't take Meto with Antipsychotics
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How much should I take? | As prescribed, don't change
- Personally-tailored – dosage varies greatly between individuals (explained here & here)
- Example .
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Do I need AEs with these? | NO. They cover all antiemetics requirements.
- If you use them regularly – you don't need any Meto or AEs.
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How do I use with Stat? | Replace AEs completely – use Stat directions – without Meto.
- Read directions and ignore any AE/Meto reference.
- Continue your AP regimen as usual (same dosage same time) .
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Quetiapine (Seroquel) is weak AE | It is considered a mild antiemetic – but still effective.
- No conclusive, definitive answer.
- Potency only above 300mg –not verified by research (dosage and clinical efficacy for vomiting).
- Receptor affinity is indicative , not conclusive.
- No simple maths here
- Accumulative effects, receptor thershold, systematic, individual parameters (weight gender).
- Lower dosages (<100mg) considered by some to be ineffective . Many 'veteran patients' still consider it to be effective (BPD_LE notes) .
- May use alternatives , well detailed here
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Stat / Regimen | |
What is it? | "Regimen/State" – only antiemetics.
Two ways to take antiemetics:
- One single dose – Stat
- Over 24h-48h – Regimen
Use only one of these schedules (either Stat or Regimen)
For antiemetics only – nothing to do wit antipsychotics , benzo , antacids , etc |
Stat or Regimen? | Both used with equal success.
Depends on your sensitivities, conditions, and preferences. |
Regimen |
- Builds tolerance – reduces side-effects
- Increased effectiveness – accumulates (also) – increased stomach tone over time
- Comfortable – feel prepared for ctb
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Stat |
- Efficacy appears similar with less hassle (no schedule)
- Less worry – like side effects during 2 days
- Comfortable – not demanding, no anxious wait, quick & simple
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So, which should I choose? | Up to you.
Regimen came from PPH, for old/fragile/sick people. This may address you, could decrease discomfort.
Stat is effective, easy option for many people. Take everything together.
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Meto . | .
(Metoclopramide). |
Warnings: | Many are fine with it; some aren't; for a few poses a risk.
Members reported other effects (non EPS):
- Serious(meto stopped):
- "I wanted to run out of my body"
- "extreme unease in body, driving me crazy"
- "made me feel very ill, my whole body"
- Mild(meto continued):
- "after taking meto went to sleep 4 hour"
- "throbbing headache"
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Prochlorperazine | Not Meto, but same warnings.
- Prochlorperazine has higher EPS risk
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Why Meto preferred? | Only antiemetic that:
- Targets both dopamine and 5HT3, and
- Crosses into the brain
This means:
- Strong stomach emptying effect
- Strong anti-vomiting vomiting effect
However alternatives (5) are fine. |
Strong effects without Meto? | Ondansetron and Domperidone target peripheral receptors, not the brain (less side effects):
Domperidone (Dopamine, less EPS)
+
Ondansetron (5HT3, less EPS)
=
Metoclopramide (Dopamine+5HT3 , Brain/EPS) |
Bad Meto reaction – what to do? | Take Diphenhydramine/Benadryl
'Failing Meto' is fine
- Use any of the other 5 on the list, or
- Ctb without antiemetics (many have done so but follow guide)
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Stat & Regimen | Guidelines |
Dosages / schedule? | Read guide. Follow everything there.
– This section is only more details not in guide –
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Meto | |
Regimen | See guide.
Schedule is however more flexible –
- Just take 3 a day over 24-48h
- morning lunch evening, 7-9h apart
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Domperidone | |
Stat | Same as meto.
Notes |
Regimen | Same as meto.
Best to stick with it. Member was fine after trying 48h regimen x 20mg (instead of 10mg)
Research concludes:
- Acummulation – "2 to 3-fold accumulation observed with repeated 4 times daily every 5 hr for 4 days."
- But only 3+ a day – "after two weeks of single 30mg per day peak plasma level almost same"
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Prochlorperazine | |
General info | Buccastem tablets are 3mg each.
Keep Benadryl/diphenhydramine on standby (used to treat EPS)
Place tablets under upper lip and wait 1-2 hours to dissolve.
Notes , Notes |
Stat | Smaller dosage– 10 to 20 mg
Suggestion: if you are small, take 4 tablets ; medium sized- 5 tablets ; large person- 6 tablets |
Regimen | Same as Meto (10mg x 3 times a day) – but final dose smaller like Stat |
Fasting | |
Is it important? | Yes, SN to intestines.
However it is flexible– don't overdo it, follow habits, see FAQ- Fasting.
- 5h – Empty stomach, partially small intestines – Good enough.
- 8h – Empty most small intestines – Good.
- 12h – Long fasting not required (may cause discomfort).
- According to your habits/feeling; if you eat just twice a day, 12h fine.
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