First Order Vs. Zero Order Kinetics

Trying to understand first order and zero order kinetics

{My own study points.}

First Order Kinetics

  • Higher plasma concentrations means higher metabolization rate.
  • Metabolism is directly proportional with drug concentrations.
  • Drug is eliminated from the body related to the plasma levels.
  • Constant half-life. (Metabolize 50% of drug)

Zero Order Kinetics

  • Higher plasma concentrations doesn't mean higher metabolization rate.
  • Metabolism is independent from plasma concentrations.
  • Drug concentration in the body increase with time disregarding the elimination rate leading to toxic side effects.
  • Constant rate of drug metabolism.


First order is Good, Zero order is BAD.

First order is occurring with most medications.

First order: constant proportion of the drug is eliminated per unit time.
Zero order: constant amount of the drug is eliminated per unit time.

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The communication structure Identify, Situation, Background, Assessment and Recommendation (ISBAR) was created to standardise the effective transfer of information in the US armed forces. ISBAR was adopted by the public health service in the 2000s




Introduction (Hello Dr. my name is) 

  • Who are you?
  • Where are you?
  • Patient's name, age, gender and department


Situation (What’s this about?) 

  • I'm calling because... (describe)
  • I have observed major changes... (ABCDE)
  • I have measured the following values...
  • (RR*, Sp020, pulse/heart rhythm, BPA, capillary refill time, etc...)
  • I have received test results...


Background (Brief & pertinent info) 

If it's urgent and/or you are concerned — speak up.

Brief and relevant case history

Admission diagnosis and date

Previous illnesses of significance

Relevant problems and treatment/interventions to date



Assessment (Your analysis and consideration of options) 

  • I think the problem/reason for the patient's condition is related to (respiration, circulation, neurology).
  • I don't know what the problem is but the patient's condition has deteriorated.
  • The patient is unstable, we need to do something.
  • I am concerned.


Recommendation (What do you want the physician to do?)

I suggest.../What interventions do you recommend?

  • Immediate intervention
  • Investigation/treatment
  • How often should I...

When should I next make contact? When will you be here?

Confirm messages and interventions with a closed loop.

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Doxorubicin chemo preparation

Doxorubicin MOA

Doxorubicin inhibits DNA and RNA synthesis by intercalation between DNA base pairs by inhibition of topoisomerase II and by steric obstruction. Doxorubicin intercalates at points of local uncoiling of the double helix. Although the exact mechanism is unclear, it appears that direct binding to DNA (intercalation) and inhibition of DNA repair (topoisomerase II inhibition) result in blockade of DNA and RNA synthesis and fragmentation of DNA. Doxorubicin is also a powerful iron chelator; the iron-doxorubicin complex can bind DNA and cell membranes and produce free radicals that immediately cleave the DNA and cell membranes.


For those who prepare chemotherapy, we always need detailed guidelines for the preparation of Doxorubicin, and all the chemo handling and preparing precautions.

Does your preparation depend on the route of administration?

Do we use the beads in all preparations, or only for the chemoembolization? 

Do we only need a chemo vertical laminar flow hoods, or the equipment we use should ensure closed system?


Doxorubicin is like any other hazardous drug that requires to be prepared under certain conditions stated in USP 800. You may refer to the latest version online. It should answer all your question regarding the precautions you must follow. Closed system devices are not enough by itself to prepare biohazard meds including chemotherapy without a primary engineering control device.

Doxorubicin is mixed with beads for particular procedure called chemoembolization in hepatocellular carcinoma and its given as intra-arterial injection by a trained provider (usually radiologist). But it is never mixed with beads for other routes.

Doxorubicin is given intravenously as a push, intermittent infusion, or continue infusion. This is usually decided by the treatment protocol you would use. For example, in AC protocol (doxorubicin and cyclophosphamide) for breast carcinoma, doxorubicin is given as IV push over 10-12 minutes. While in a more complicated protocol such as R-EPOCH, it is combined with other chemotherapy drugs and is infused as a continuous infusion over 24 hours for multiple days.

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How tech is transforming healthcare

How tech is transforming healthcare



Data captured from health devices could provide precious information to provide accurate care to the patients.
As we noticed wearable gadgets are increasing in numbers as well as accuracy.


Augmented Reality

Allowing the healthcare providers to jump instantly between patients, or view organs, or even project radiology images over the body during operations to reduce mistakes.
Combining live video-streaming with Augmented Reality surgeons carrying out operations are able to consult the other side of the world. Who says that you can’t be in two places at once?


Online Consultation

The patient, who can afford it, can always consult with their preferred healthcare providers online and even afford a sort of on-call medical service, other than emergency services.

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innohep – tinzaparin sodium

Bringing the freedom to focus


tinzaparin sodium

Get ready to meet your new friend

“A baby is something you carry inside you for nine months, in your arms for three years, and in your heart until the day you die.”

- Mary Mason -

Antenatal assessment and management (to be assessed at booking and repeated if admitted)

Any previous VTE except a Single event related to major surgery


Requires antenatal prophylaxis with LMWH
refer to trust-nominated thrombosis in pregnancy expert/team

Hospital admission

Single previous VTE related to major surgery

High-risk thrombophilia + no VTE

Medical comorbidities e.g. cancer, heart failure, active SLE, IBD or inflammatory polyarthropathy, nephrotic syndrome, type 1 DM with nephropathy, sickle cell disease, current IVDU

Any surgical procedure e.g. appendicectomy

OHSS(first trimester only)


Consider antenatal prophylaxis with LMWH

Obesity (BMI > 30KG/M2)


Parity ≥ 3


Gross varicose veins

Current pre-eclampsia

Immobility, e.g. paraplegia, PGP

Family history of unprovoked or estrogen-provoked VTE in first-degree relative

Low-risk thrombophilia

Multiple pregnancy


Transient risk factors:

Dehydration/hyperemesis; current systemic infection; long-distance travel

Fewer than three risk factors

Four or more risk factors:
Prophylaxis from first trimester

Three risk factors:
Prophylaxis from 28 weeks


Mobilisation and avoidance of dehydration

For more information

Regarding the timing of first antenatal and/or postnatal thromboprophylactic dose; please refer to RCOG Green-Top Guideline No. 37a (thrombosis and Embolism during Pregnancy and the Puerperium, Reducing the risk - Published 13/04/2015)

Postnatal assessment and management (to be assessed on delivery suite)

Any previous VTE
anyone requiring antenatal LMWH
High-risk thrombophilia
Low-risk thrombophilia + FHx


At least 6 weeks, postnatal prophylactic LMWH

caesarean section in labour


Readmission or prolonged admission (≥3 days) in the puerperium

Any surgical procedure int the puerperium except immediate repair of the perineum

Medical comorbidities e.g. cancer, heart failure, active SLE, IBD or inflammatory polyarthropathy, nephrotic syndrome, type 1 DM with nephropathy, sickle cell disease, current IVDU


At least 10 days postnatal prophylaxis with LMWH

NB if presisting > 3 risk factors; consider extending thromboprophylaxis with LMWH

Age > 35 years
Obesity (BMI > 30KG/M2)
Parity ≥ 3
Elective caesarean section
Family history of VTE
Low-risk thrombophilia
Gross varicose veins
Current systemic infection
Current pre-eclampsia
Immobility, e.g. paraplegia, PGP, long-distance travel
Multiple pregnancy
Preterm delivery in this pregnancy (<37+0 weeks)
Stillbirth in this pregnancy
Mid-cavity rotational or operative delivery
Prolonged labour (< 24 hours)
PPH > 1 litre or blood transfusion
Family history of unprovoked or estrogen-provoked VTE in first-degree relative
Low-risk thrombophilia
Multiple pregnancy
Two or more risk factors
Fewer than two risk factors


Mobilisation and avoidance of dehydration

Antenatal and post natal prophylactic dose of LMWH

Weight < 50KG = 20MG enoxaparin / 2500UNITS dalteparin / 3500UNITS tinzaparin daily.
Weight 50-90KG = 40MG enoxaparin / 5000UNITS dalteparin / 4500UNITS tinzaparin daily.
Weight 91-130KG = 60MG enoxaparin / 7500UNITS dalteparin / 7000UNITS tinzaparin daily.
Weight 131-170KG = 80MG enoxaparin / 10000UNITS dalteparin / 9000UNITS tinzaparin daily.
Weight > 170KG = 0.6MG/KG enoxaparin / 75UNITS/KG dalteparin / 75UNITS/KG tinzaparin daily.

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octaplex – Prothrombin Complex Concentrate

Accurate prevention and fast control of life-threatening bleeding.
octaplex® provides a rapid and complete reversal of vitamin K antagonists (VKA) induced coagulopathy due to:
  • Easy storage at room temperature and quick availability.
  • Small infusion volume with no risk of fluid overload.
  • Short infusion time.
  • No need for blood type matching.
  • Balanced content of vitamin K coagulation factors and inhibitory proteins.
octaplex is ready to be used in life-threatening bleeding, unlike FFP:




2100ML (30ML/KG)

10 minutes

14-50 hours

Blood matching not required

Blood matching is required

Used immediately in room temperature

thawing time: 30 minutes

  1. Dowlatshahi, D., Butcher, K. S., Asdaghi, N., Nahirniak, S., Bernbaum, M. L., Giulivi, A., … Coutts, S. B. (2012). Poor Prognosis in Warfarin-Associated Intracranial Hemorrhage Despite Anticoagulation Reversal. Stroke43(7), 1812-1817. doi:10.1161/strokeaha.112.652065
  2. Lubetsky, A., Hoffman, R., Zimlichman, R., Eldor, A., Zvi, J., Kostenko, V., & Brenner, B. (2004). Efficacy and safety of a prothrombin complex concentrate (Octaplex®) for rapid reversal of oral anticoagulation. Thrombosis Research113(6), 371-378. doi:10.1016/j.thromres.2004.04.004
  3. Management of severe perioperative bleeding. (2014). European Journal of Anaesthesiology31(4), 247. doi:10.1097/eja.0000000000000066
  4. Varga, C., Al-Touri, S., Papadoukakis, S., Caplan, S., Kahn, S., & Blostein, M. (2012). The effectiveness and safety of fixed low-dose prothrombin complex concentrates in patients requiring urgent reversal of warfarin (CME). Transfusion53(7), 1451-1458. doi:10.1111/j.1537-2995.2012.03924.x

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Improving Patient’s Safety By Controlling The Doctor Orders For Ranged Dose Or Ranged Frequency.

Improving Patient’s Safety By Controlling The Doctor Orders For Ranged Dose Or Ranged Frequency.

Are you familiar with range orders for medications like MORPHINE 2-9MG IV Q6hr PRN at your facility? Does your hospital policy contains any restrictions on these orders?! And in case of a ranged order; how does the nurse determine the exact dose to be given and at which frequency?!

Where I work, we do allow them, and the nurse is giving all the needed training for pain assessment. We’re also using an electronic system, where prescriber must enter the required indication for each scenario. And not leaving the medication order prune to error and assumptions of the other healthcare staff.

Other hospitals might only allow one range... perhaps dose or maybe frequency! Yet, in both cases, the physicians must clearly enter the required dose range [i.e. for pain score 1-3 give 2MG, for pain scale 4-9 give 4MG …. etc.]

In some cases if the physician does not specify – the lowest dose and shortest frequency are used. A nurse must start at the lowest dose unless the patient has recently received a higher dose of the medication (or equivalent)

During the doctor's entry for the ranged order, they were using a free text field, and that doesn’t really help our clinical support system. That's why in most cases we had to verify the ranged doses manually and double checking them while dispensing and administration.

For orders with insulin doses from our insulin pumps and doses from our PCAs; ranged orders are required.

For non-pain medications, we instruct the nurse to start low and assess for effect, then proceed as necessary to address the condition.   Also have a Pain Management policy that guides the nurse to choose the pain order and dose that matches the pain score obtained from the assessment of the patient pain medication asks the prescriber to choose a Pain severity (mild, moderate or severe), all of which have scores assigned to them in the policy. For example, if the dose range is 1-2MG when mild pain, and the patient expressed the higher end of that range, then the nurse would choose 2MG.  If there are multiple products ordered, the nurse first picks the one attached to the pain score and then determines the dose which gives the nurse a guideline, but allows some flexibility in adjusting to the patient response.

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A common medical abbreviation for urgent or rush. From the Latin word statum, meaning 'immediately.'

Often used in medical contexts.

The patient's heart just stopped working.
We need a defibrillator in here stat!

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